Increased Sensitivity to Long-term 5-Fluorouracil Exposure of Human Colon Cancer HT-29 Cells Resistant to Short-term Exposure

A 5-fluorouracil (5-FU)-resistant subline of human colon cancer HT-29 cells was developed by repeated 1-h exposure in vitro to 5-FU. This subline (HT-29/5-FU/S) had 8-fold resistance to 5-FU in a 1-h exposure assay. However, it had rather increased sensitivity to 5-FU when assayed after a continuous 96-h exposure to it. Significantly less 5-fluorouridine-5'-triphosphate was produced in the resistant cells, leading to a lower level of 5-FU incorporation into the cellular RNA. The reduced activity of orotate phosphoribosyltransferase might explain these results. In contrast, the HT-29/5-FU/S cells were more sensitive to the inhibition of in situ thymidylate synthase (TS) by 5-FU than were the parent cells. The lower in situ TS activity may have made HT-29/5-FU/S cells more sensitive to TS inhibition by 5-FU as compared with the parent cells. The fact that HT-29/5-FU/S was more resistant to short-term 5-FU exposure but more sensitive to long-term exposure than the parent line confirmed the existence of different modes of action of 5-FU, depending on the exposure time.     

Alterations of theTP53 gene and TP53 protein expression in epithelial ovarian cancer before and after chemotherapy

Background A role for theTP53 (alias p53) tumor-suppressor gene in chemoresistance has recently been discussed, but little is known about the clinical relevance of theTP53 gene to chemoresistance. To elucidate the relevance ofTP53 status to chemoresistance, we investigated theTP53 gene and TP53 protein expression in tumors from the same patients, before and after chemotherapy. Methods Twenty-one patients with ovarian cancer, who had residual disease after primary surgery, were studied. These patients received chemotherapy consisting of cisplatin, doxorubicin, and cyclophosphamide, and then underwent a second surgery. Polymerase chain reaction-single strand conformation polymorphism analysis and cycle sequencing were performed to determineTP53 mutation. TP53 protein was detected by Western blot analysis. Results Of the 21 patients studied, 9 responded to chemotherapy. Mutation of theTP53 gene was seen in 7 patients (2 responders and 5 nonresponders) before chemotherapy. After chemotherapy, another mutation of the gene was observed in 5 patients, all of whom were nonresponders. TP53 protein was detected in 10 patients (3 responders and 7 nonresponders) before chemotherapy. After chemotherapy, the expression of TP53 protein increased in these 3 nonresponders, and became positive in 2 other nonresponders. Conclusions This study showed for the first time in clinical investigation that alterations toTP53 could develop in association with chemotherapy, and thatTP53 status may relate to the mechanisms of chemoresistance in patients with epithelial ovarian cancer.     

Pain and Bradykinin Receptors--sensory transduction mechanism in the nociceptor terminals and expression change of bradykinin receptors in inflamed condition]

Bradykinin (BK), an endogenous algesic and sensitizing substance, excited nociceptors and sensitized their heat responses. These effects were mediated by B2 receptors (B2Rs) in normal condition, and B1 receptors were additionally recruited in inflammation. B2Rs were coupled with Gq/11 and their activation resulted in diacylglycerol and inositol triphosphate release. Diacylglycerol activated protein kinase (PK) Cepsilon in sensory neurons. To clarify what channel was modulated by PKC to depolarize nociceptor terminals, we examined the heat activation threshold (Tt) of heat-sensitive capsaicin receptor (TRPV1). Tt was lowered down to 31 degrees C by BK in concentration dependent manner through activation of PKCepsilon in cells heterologously expressing TRPV1 and B2Rs. Thus both excitation and sensitization to heat could be explained by one mechanism, lowering Tt of TRPV1. The same was observed in capsaicin-sensitive primary sensory neurons. However, TRPV1 knockout mice showed almost no change in BK-induced nociceptive behavior and nociceptor excitation, although BK-induced heat hyperalgesia completely disappeared, suggesting that TRPV1 was not the sole channel that was modulated by BK to depolarize nociceptor terminals. In addition nociceptor sensitivity to BK was augmented in inflamed animals, with B2R mRNA and protein upregulated. The mechanism for prostaglandin-induced augmentation of BK response is left open for future study.     

Vaccination of dendritic cells loaded with interleukin-12-secreting cancer cells augments in vivo antitumor immunity: characteristics of syngeneic and allogeneic antigen-presenting cell cancer hybrid cells.

Cancer immunotherapy by fusion of antigen-presenting cells and tumor cells has been shown to induce potent antitumor immunity. In this study, we characterized syngeneic and allogeneic, murine macrophage/dendritic cell (DC)-cancer fusion cells for the antitumor effects. The results showed the superiority of allogeneic cells as fusion partners in both types of antigen-presenting cells in an in vivo immunotherapy model. A potent induction of tumor-specific CTLs was observed in these immunized conditions. In addition, the immunization with DC-cancer fusion cells was better than that with macrophage-cancer fusion cells. Both syngeneic and allogeneic DC-cancer fusion cells induced higher levels of IFN-gamma production than macrophage-cancer fusion cells. Interestingly, allogeneic DC-cancer fusion cells were superior in that they efficiently induced Th1-type cytokines but not the Th2-type cytokines interleukin (IL)-10 and IL-4, whereas syngeneic DC-cancer fusion cells were powerful inducers of both Th1 and Th2 cytokines. These results suggest that allogeneic DCs are suitable as fusion cells in cancer immunotherapy. To further enhance the antitumor immunity in the clinical setting, we prepared DCs fused with IL-12 gene-transferred cancer cells and thus generated IL-12-secreting DC-cancer fusion cells. Immunization with these gene-modified DC-cancer fusion cells was able to elicit a markedly enhanced antitumor effect in the in vivo therapeutic model. This novel IL-12-producing fusion cell vaccine might be one promising intervention for future cancer immunotherapy.     

Improved trends in survival and engraftment after single cord blood transplantation for adult acute myeloid leukemia

Unrelated cord blood transplantation (CBT) is an alternative curative option for adult patients with acute myeloid leukemia (AML) who need allogeneic hematopoietic cell transplantation (HCT) but lack an HLA-matched related or unrelated donor. However, large-scale data are lacking on CBT outcomes for unselected adult AML. To investigate the trends of survival and engraftment after CBT over the past 22 years, we retrospectively evaluated the data of patients with AML in Japan according to the time period of CBT (1998–2007 vs 2008–2013 vs 2014–2019). A total of 5504 patients who received single-unit CBT as first allogeneic HCT for AML were included. Overall survival (OS) at 2 years significantly improved over time. The improved OS among patients in ≥ complete remission (CR)3 and active disease at CBT was mainly due to a reduction of relapse-related mortality, whereas among patients in first or second CR at CBT, this was due mainly to a reduction of non-relapse mortality. The trends of neutrophil engraftment also improved over time. This experience demonstrated that the survival and engraftment rate after CBT for this group has improved over the past 22 years.Subject terms: Acute myeloid leukaemia, Cancer immunotherapy     

Atorvastatin Reduces Circulating S100A12 Levels in Patients with Carotid Atherosclerotic Plaques - A Link with Plaque Inflammation

Aims: Inflammation is involved in various processes of atherosclerosis development. Serum C-reactive protein (CRP) levels, a predictor for cardiovascular risk, are reportedly reduced by statins. However, several studies have demonstrated that CRP is a bystander during atherogenesis. While S100A12 has been focused on as an inflammatory molecule, it remains unclear whether statins affect circulating S100A12 levels. Here, we investigated whether atorvastatin treatment affected S100A12 and which biomarkers were correlated with changes in arterial inflammation. Methods: We performed a prospective, randomized open-labeled trial on whether atorvastatin affected arterial (carotid and thoracic aorta) inflammation using¹⁸fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) and inflammatory markers. Thirty-one statin-naïve patients with carotid atherosclerotic plaques were randomized to either a group receiving dietary management (n=15) or one receiving atorvastatin (10mg/day,n=16) for 12weeks.¹⁸F-FDG-PET/CT and flow-mediated vasodilation (FMD) were performed, the latter to evaluate endothelial function. Results: Atorvastatin, but not the diet-only treatment, significantly reduced LDL-cholesterol (LDL-C, -43%), serum CRP (-37%) and S100A12 levels (-28%) and improved FMD (+38%).¹⁸F-FDG-PET/CT demonstrated that atorvastatin, but not the diet-only treatment, significantly reduced accumulation of¹⁸F-FDG in the carotid artery and thoracic aorta. A multivariate analysis revealed that reduction in CRP, S100A12, LDL-C, oxidized-LDL, and increase in FMD were significantly associated with reduced arterial inflammation in the thoracic aorta, but not in the carotid artery. Conclusions: Atorvastatin treatment reduced S100A12/CRP levels, and the changes in these circulating markers mirrored the improvement in arterial inflammation. Our observations suggest that S100A12 may be an emerging therapeutic target for atherosclerosis.     

Mortality among persons with a history of Kawasaki disease in Japan: Can paediatricians safely discontinue follow-up of children with a history of the disease but without cardiac sequelae?

Aim: To clarify the question of whether patients with Kawasaki disease suffer a higher mortality rate after the incidence of the disease in comparison with age-matched healthy individuals. Methods: Between July 1982 and December 1992, 52 collaborating hospitals collected data on all patients having a new, definite diagnosis of Kawasaki disease. Patients were followed up until 31 December 2001 or their death. The expected number of deaths was calculated from Japanese vital statistics data and compared with the observed number. Results: Of 6576 patients enrolled, 29 (20 males and 9 females) died. The standardized mortality ratio (SMR: the observed number of deaths divided by the expected number of deaths based on the vital statistics in Japan) was 1.15 (95% CI: 0.77-1.66). In spite of the high SMRs during the acute phase, the mortality rate was not high after the acute phase for the entire group of patients. Although the SMR after the acute phase was 0.75 for those without cardiac sequelae, six males (but none of the females) with cardiac sequelae died during this period; and the SMR for the male group with cardiac sequelae was 1.95 (95% CI: 0.71-4.25). The mortality from congenital anomalies of the circulatory system was elevated, but no increase in cancer deaths was observed.

Conclusion: Although it was not statistically significant, the mortality rate among males with cardiac sequelae due to Kawasaki disease appeared to be higher than in the general population. On the other hand, the mortality rates for females with the sequelae and both males and females without sequelae were not elevated.