OBJECTIVE: To explore the expression of cellular apoptosis susceptibility protein （CAS） in acute myeloid leukemia （AML） and its correlation with clinical characteristics. METHODS: The expression of CAS in bone marrow tissue of 54 patients with AML and 24 patients with non-hematological malignant diseases was detected by Western blot and immune-histochemical method, and compared between AML group and control group. Also the relationship of CAS expression in AML and sex, age, WBC count, Hb, platelet count, bone marrow blast cell ratio, ki-67 index, cytogenetic and molecular biological prognostic risk stratification, extramedullary infiltration and other clinical characteristics was analyzed. RESULTS: Western blot showed that the expression of CAS protein in bone marrow biopsies of AML patients was significantly higher than that in control group (P<0.05). Immune-histochemical method revealed that CAS was mainly located in the cytoplasm in both AML group and control group. Among 54 AML patients, 14 patients (25.9%) showed high expression of CAS, while all the 24 patients in the control group showed low expression of CAS. The high expression rate of CAS in AML patients was significantly higher than that in the control group (P<0.05). There were statistically significant differences in prognostic risk stratification and the remission rate of the first chemotherapy between CAS high expression group and CAS low expression group in AML (P<0.05). The proportion of high risk patients and unremission patients after the first chemotherapy in CAS high expression group were significantly higher than those in CAS low expression group (57.1% vs 27.5%, 30.8% vs 7.9%), while the proportion of low risk patients and complete remission patients after the first chemotherapy were significantly lower than those in CAS low expression group (14.3% vs 37.5%, 53.8% vs 84.2%). In AML patients, the ki-67 index of bone marrow tissue in CAS high expression group was higher than that in CAS low expression group (60% vs 50%) (P<0.05). CONCLUSION CAS is localized in cytoplasm in both AML and non-hematological malignant diseases, and its expression increases in AML. CAS is related to the risk stratification of cytogenetics and molecular biology, the remission rate after the first chemotherapy and ki-67 index in AML, which suggests that CAS may be involved in the occurrence and development of AML.
Bone Marrow/metabolism* ; Cellular Apoptosis Susceptibility Protein/metabolism* ; Humans ; Ki-67 Antigen/metabolism* ; Leukemia, Myeloid, Acute/drug therapy* ; Prognosis ; Remission Induction

OBJECTIVETo investigate the expression change of apoptosis-associated genes in human colon cancer cells transplanted into nude mice after hyperthermia, chemotherapy and radiotherapy.

METHODSHuman colon cancer cell line HT29 was transplanted into the hind limbs of nude mice. Under the laboratory-simulated condition of hyperthermia(43 degree centigrade, 60 min), actual radiation doses and MMC doses were calculated in reference to the clinical practice. The mice were divided into 6 groups according to the treatment approaches: hyperthermia (group A), chemotherapy (group B), radiotherapy (group D), thermochemotherapy (group C), thermoradiotherapy (group E) and thermochemoradiotherapy (group F). The mice were sacrificed at different time points and the tumor tissues were taken for further procedures. The morphologic changes of P53, Bcl-2 and Bax expression in membrane, cytoplasm and nucleus of tumor cell after treatment were observed by immunohistochemistry stain (SP method).

RESULTSAll of the six approaches of treatment could down-regulate the expression of P53 and Bcl-2, and up-regulate the expression of Bax in different levels. There was no significant difference in the amount of reduction of P53 expression among group A, C and E. The extent of reduction in the above mentioned groups was significantly different as compared to group B and D. By comparing to group D, the extent of reduction of P53 expression was greater in group B. Down-regulation of Bcl-2 could be enhanced when hyperthermia was combined with chemotherapy (group C) or radiation (group E), but more obvious down-regulation was found in group E as compared to group C. Hyperthermia itself could not obviously up-regulate Bax expression, and it occurred at last. Bax expression increased more by chemotherapy treatment (group B) than that by radiation (group D). By comparing to group C, the greater increase occurred in group E.

CONCLUSIONSHyperthermia enhances the effects of radiosensitivity and chemosensitivity on tumors by changing the expression of apoptosis-associated genes P53, Bcl-2 and Bax. Hyperthermia combined with chemotherapy and/or radiation has a greater effect on down-regulation of P53 and Bcl-2 expression and up-regulation of Bax expression than any single therapy.

Animals ; Apoptosis ; Cell Line, Tumor ; Cellular Apoptosis Susceptibility Protein ; metabolism ; Chemotherapy, Adjuvant ; Colonic Neoplasms ; metabolism ; therapy ; Combined Modality Therapy ; Humans ; Hyperthermia, Induced ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Radiotherapy, Adjuvant ; Tumor Suppressor Protein p53 ; metabolism ; bcl-2-Associated X Protein ; metabolism