[Expression change of apoptosis-associated genes after hyperthermia, chemotherapy and radiotherapy in human colon cancer-transplanted nude mice].

OBJECTIVE: To investigate the expression change of apoptosis-associated genes in human colon cancer cells transplanted into nude mice after hyperthermia, chemotherapy and radiotherapy. METHODS: Human 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). RESULTS: All 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. CONCLUSIONS: Hyperthermia 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.

[Management of nonfunctioning islet cell tumors of the pancreas].

OBJECTIVE: To analyze the clinical and pathological features in order to investigate appropriate way of diagnosis and treatment for non-functional islet cell tumors of the pancreas (NFICT). METHODS: The data and experience of surgically treated 43 patients with pathologically confirmed NFICT over the last 30 years were retrospectively reviewed. The survival rate was estimated using Kaplan-Meier method and the potential risk factors affecting survival were compared with Log rank test. RESULTS: There were 7 males and 36 females in this series with a mean age of 31.6 years ranged from 8 to 67 years. Twenty-eight patients were diagnosed as having non-functional islet cell carcinomas of the pancreas (NFICC) and 15 patients benign islet cell tumors. The most common symptoms in NFICT were abdominal pain 55.8%, nausea and/or vomiting (32.6%), fatigue (25.6%) and abdominal mass (23.3%). Preoperatively, all of those were found to have a mass in their pancrease by ultrasonic and computed tomography examination, with 21 in the head, 10 in the body and 6 in the tail of the pancreas. Multicemtric tumor were found in one patient. Thirty-nine of these 43 patients (90.7%) underwent surgical resection, with a curative resection in 30 (69.8%) and palliative in 9 (20.9%). The resectability and curative resection rate in 28 patients with nonfunctioning islet cell carcinomas of the pancreas was 78.6% and 60.7%, respectively. None of the 15 patients with benign nonfunctioning islet cell tumor of the pancreas died of this disease. While the overall cumulative 5- and 10-year survival rate in 28 patients with non-functional islet cell carcinomas of the pancreas was only 58.1% and 29.0%, respectively. Curative resection, female, younger than 30 years old and mass diameter < 10 cm were found to be positive prognostic factors. But multivariate Cox regression analysis indicated that radical resection was the only independent prognostic factor (P = 0.007). CONCLUSION: Nonfunctioning islet cell tumor of the pancreas is frequently found in young female. Surgical resection, especially curative resection can achieve satisfactory long-term survival.

Change in expression of apoptosis genes after hyperthermia, chemotherapy and radiotherapy in human colon cancer transplanted into nude mice.

AIM: To investigate the change in expression of p53, Bcl-2, and Bax genes in human colon cancer cells transplanted into nude mice after hyperthermia, chemotherapy, radiotherapy, thermochemotherapy, thermoradiotherapy and thermochemoradiotherapy. METHODS: Human colon cancer cell line (HT29) was transplanted into the hind limbs of nude mice. Under laboratory simulated conditions of hyperthermia (43 centigrade, 60 min), the actual radiation doses and doses of mitomycin C (MMC) were calculated in reference to the clinical radiotherapy for human rectal cancer and chemotherapy prescription for colon cancer. The mice were divided into 6 groups according to the treatment approaches: hyperthermia, chemotherapy, radiotherapy, thermochemotherapy, thermoradiotherapy, and thermochemoradiotherapy. The mice were sacrificed at different time points and the tumor tissue was taken for further procedures. The morphologic changes in membrane, cytoplasm and nuclei of tumor cells of p53, Bcl-2, and Bax after treatment, were observed by immunohistochemistry staining. RESULTS: All of the six treatment modalities down-regulated the expression of p53, Bcl-2 and up-regulated the expression of Bax at different levels. The combined therapy of hyperthermia, with chemotherapy, and/or irradiation showed a greater effect on down-regulating the expression of p53 (0.208 +/- 0.009 vs 0.155 +/- 0.0115, P < 0.01) and Bcl-2 (0.086 +/- 0.010 vs 0.026 +/- 0.0170, P < 0.01) and up-regulating Bax expression (0.091 +/- 0.0013 vs 0.207 +/- 0.027, P < 0.01) compared with any single therapy. CONCLUSION: Hyperthermia enhances the effect of radio- and chemotherapy on tumors by changing the expression of apoptosis genes, such as p53, Bcl-2 and Bax.

[Screening, cloning and identification of the human endometrial carcinoma-related genes].

OBJECTIVE: To screen, clone and identify the cDNA fragments of human endometrial carcinoma-related genes,and explore the molecular mechanism of endometrial carcinogenesis. METHODS: Pure endometrial glandular epithelial cells and endometrial carcinoma cells were obtained by laser capture microdissection (LCM). RNA from these cells was isolated, and differentially expressed gene fragments that were specialy relevant to endometrial carcingenesis were identified by using fluorescence differential display reverse transcription polymerase chain reaction (FDD-PCR). The selected fragments were cloned, sequenced and verified by reverse Northern blot analysis, and positive fragments were BLAST analysed and compared with those in Genbank. RESULTS: 38 differential fragments were isolated, 3 of which were expressed more abundantly in normal endometrium and 35 were highly expressed in endometrial carcinoma. 10 fragments were recoverd, cloned and sequenced, confirmed by reverse Northern blot analysis, among which 6 fragments were positive. BLAST analysis showed that T1.1 was homologous to cyclin-dependent protein kinase 7 (CDK7, 99%); L1.9 was homologous to protein phosphatase 1 regulatory (inhibitor) subunit 12A (PPP1R12A, 99%); L1.21 and L1.22 were homologous to cellular repressor of E1A-stimulated genes 1 (CREG, 100%); L1.25 and L1.26 were homologous to solute carrier family 39 (zinc transporter) member 10 (SLC39A10, >98%). CONCLUSION: Gene fragments related to endometrial carcinoma have been obtained by applying LCM and FDD-PCR. To our knowledge it is the first time that the correlation between CDK7, PPP1R12A, CREG, SLC39A10 and endometrial carcinoma is discovered at mRNA level, and their role in molecular mechanism of cancinogenesis is discussed. CDK7, CREG, SLC39A10 as new candidate oncogene and PPP1R12A as new candidate anti-oncogene are worthy of being further investigated in the future.

[Change in E-cadherin, alpha-, beta- and gamma-catenin expression after hyperthermia of a human colon carcinoma cell line in vitro].

OBJECTIVE: To investigate changes in E-cadherin, alpha-, beta-, and gamma-catenin expression after hyperthermia of a human colon cancer cell line in vitro. METHODS: E-cadherin and alpha-, beta-, and gamma-catenin expression on a human colon carcinoma cell line HT29 at 7 successive times after hyperthermia at 43 degrees C for 60 min were investigated in vitro by RT-PCR and immunochemistry. RESULTS: In vitro studies revealed that E-cadherin expression had increased significantly on HT29 cells at 24 hours after hyperthermia at 43 degrees C for 60 min. In a time-course analysis, the expression of E-cadherin had major increase at 24 to 72 hours after hyperthermia compared with an unheated control cell. gamma-catenin expression had increased significantly at 8 to 72 hours. After hyperthermia at 43 degrees C for 60 min, beta-catenin expression had decreased gradually at 4 hours to 72 hours. alpha-catenin expression kept unchanged after hyperthermia. CONCLUSION: Hyperthermia at 43C for 60 min upregulated E-cadherin and gamma-catenin expressions but downregulated beta-catenin expression on colon carcinoma cells in vitro. alpha-catenin expression was not regulated by hyperthermia.