Neutron-induced apoptosis of HR8348 cells in vitro

Cell killing, nuclear damage and apoptosis in Chinese hamster V79 cells after irradiation with heavy-ion beams of (16)O, (12)C and (7)Li

Chinese hamster V79 cells were exposed to high LET (linear energy transfer) (16)O-beam (625keV/mum) radiation in the dose range of 0-9.83Gy. Cell survival, micronuclei (MN), chromosomal aberrations (CA) and induction of apoptosis were studied as a follow up of our earlier study on high LET radiations ((7)Li-beam of 60keV/mum and (12)C-beam of 295keV/mum) as well as (60)Co gamma-rays. Dose dependent decline in surviving fraction was noticed along with the increase of MN frequency, CA frequency as well as percentage of apoptosis as detected by nuclear fragmentation assay. The relative intensity of DNA ladder, which is a useful marker for the determination of the extent of apoptosis induction, was also increased in a dose dependent manner. Additionally, expression of tyrosine kinase lck-1 gene, which plays an important role in response to ionizing radiation induced apoptosis, was increased with the increase of radiation doses and also with incubation time. The present study showed that all the high LET radiations were generally more effective in cell killing and inflicting other cytogenetic damages than that of low LET gamma-rays. The dose response curves revealed that (7)Li-beam was most effective in cell killing as well as inducing other nuclear damages followed by (12)C, (16)O and (60)Co gamma-rays, in that order. The result of this study may have some application in biological dosimetry for assessment of genotoxicity in heavy ion exposed subjects and in determining suitable doses for radiotherapy in cancer patients where various species of heavy ions are now being generally used.

Expression of cyclooxygenase-2 in pancreatic cancer and its correlation with p53

AIM: To investigate the expressions of COX-2 and p53 in human pancreatic cancer and their correlation with biological behaviors of pancreatic cancer.

METHODS: The expressions of COX-2 and p53 in 51 specimens of human pancreatic ductal adenocarcinoma and 11 specimens of normal tissues adjacent human pancreatic ductal adenocarcinoma were detected with immunohistochemistry by Envision.

RESULTS: The detectable rate of COX-2 and p53 in pancreatic ductal adenocarcinoma were 74.5% and 60.8%, respectively; but none in adjacent normal tissues. The expression of COX-2 was significantly associated with the clinical stages and metastasis status of lymph nodes (P = 0.022, 0.036), but not with histological grade (P = 0.152). The expression of p53 was significantly correlated with the lymph node metastasis status (P = 0.035), but not with their histological grades and clinical stages (P = 0.131, 0.078). There was a significant correlation between the expression of COX-2 and p53 (r = 0.452, P = 0.001). Conditions such as age, sex, tumor size and location had no relation with expression of COX-2 or p53.

CONCLUSION: The cooperation of COX-2 and p53 may play a pivotal role in the carcinogenesis and the progression in pancreatic cancer. They may provide new targets for the therapy of pancreatic cancer.

Arterial chemotherapy of 5-fluorouracil and mitomycin C in the treatment of liver metastases of colorectal cancer

AIM: Regional chemotherapy using hepatic artery catheters is a good method of treating patients with colorectal cancer liver metastases. We investigated the survival of patients with liver metastases from colorectal cancer using 5-fluorouracil (5-FU) and mitomycin C Cthrough implantable hepatic arterial infusion port.

METHODS: Seventy-five patients with inoperable liver metastases from colorectal cancer were included between March, 1992 and November, 2001. We placed implantable hepatic arterial catheter (HAC) port by laparotomy.5-FU, 1000 mg/m²/d continuous infusion for five days every four weeks, was delivered in the hepatic arterial catheter through the port. Mitomycin C, 30 mg/m²/d infusion in the first day every cycle through the port. Response to the treatment was evaluated by serial determinations of plasma CEA and imaging techniques consisting of computerized tomography and sonography of liver.

RESULTS: Sixty-eight were performed hepatic artery chemotherapy and fifty-six were followed up among seventy-five HAC patients. Twenty-six patients (46.4%) have responded and 4 complete remission were achieved. Eight patients (14.3%) had stable liver metastases. Twenty-two patients (39.3%) were progressed with increased tumor size and number. Twenty-nine patients (51.8%) had a decreased serum CEA level, while 10 patients (17.9%) were stable and 17 patients (30.4%) had an increased serum CEA level. There were no operative death in this series. Complications, which occurred in 18 patients (32.1%), were as followed: hepatic artery thrombosis in 11, Upper gastric and intestinal bleeding in 3, liver abscess in 1, pocket infection in 1, cholangitis in 1, and hepatic artery pseudo-aneurysm in one patient.

CONCLUSION: Combined infusion of 5-FU and mitomycin C by hepatic artery catheter port is an effective treatment for liver metastases from colorectal cancer. The high response and lower complication rates prove the adjuvant treatment of colorectal cancer with this treatment.