Effects of Imbalance of Apoptosis and Proliferation on Large Bowel Carcinogenesis in Mice

OBJECTIVE To observe the pattern of changes in the proliferation and apoptosis at different stages of large bowel carcinoma in mice, and to explore the effects of the imbalance of apoptosis and proliferation at different stages of large-intestine carcinogenesis.METHODS An experimental animal model for large intestine carcinogenesis of KUNMING-strain mice was used. The carcinomas were induced by subcuteneous injection of dimethylhydrazine (DMH) and the distribution and density changes of proliferating and apoptotic cells observed through multistages toward cancer formation. The animals were killed in groups at the 12th, 18th, 24th,and 32nd weeks of carcinoma induction. The apoptotic and proliferating cells were labeled separately using TUNEL and PCNA immunohistochemical staining methodsRF, RESULTS In the normal mouse mucosa, all the apoptotic cells were situated in the superficial layers, however, the proliferating cells were situated in the basement layers, and the amount of both were small. In the early stage of carcinoma induction, the proliferation and the apoptotic cells slightly increased in amount, but there were no obvious changes in their ratio. In the medium stage, the densities of both distinctly increased, but there were no obvious changes in the ratio. In the late stage, the densities of the proliferating and the apoptotic cells in the non-carcinoma mucosa were higher than those at other stages. The proliferating cells in the dysplastic mucosa increased progressively with the increasing degree of the lesions. Although the apoptotic cells increased, their changes did not occur with the degree of the lesions. Their ratio showed a decreasing tendency with the degree of the lesions.CONCLUSIONS (①The presence of an imbalance between cell proliferation and apoptosis was confirmed in the course of large intestine carcinogenesis in a mouse model. ②In the early stage of carcinoma induction both proliferation and apoptosis were at a low level; in the medium stage, they were both at a high level; and in the late stage (that is in carcinoma), proliferation was at a very high level, while apoptosis was at a low level. ③The proliferating cells increased progressively with the degree of dysplasia. There were no obvious changes in the apoptotic cells and their ratio to the proliferating cell sshowed a progressively increasing tendency. ④In the stage of cancer formation, the most essential change was the excessive decrease in the ratio of apoptosis to proliferation. These results support the hypothesis of “Cell Selective Proliferation“, which was raised by authors previously in a study on human large bowel carcinoma.     

Effects of life event stress and social support on the odds of a ≥2 cm breast cancer

Objective  To examine the contribution of life event and social support factors to diagnosis with a ≥2 cm breast cancer. Methods  We studied 1,459 Australian women aged 40–69 diagnosed in 2002–2003 with a first primary invasive breast cancer 1.1 cm or larger. We measured stressful life events, perceived stress levels, and social support in the year before diagnosis and collected information on other potential risk factors and confounders. Results  The odds of a ≥2 cm breast cancer relative to a 1.1–1.9 cm breast cancer were reduced in women who reported tension or change in an intimate relationship in the year before diagnosis (OR = 0.71 95% CI 0.54–0.92; p = 0.009); the reduction was greatest in women living with a partner (OR = 0.64 95% CI 0.47–0.88; p = 0.006) and was largely unaffected by adjustment for other variables independently associated with a ≥2 cm breast cancer in our study. There was no evidence that the total number or severity of all studied life events influenced cancer size. Low partner support increased the odds of a ≥2 cm cancer but only in women not living with a partner. Conclusion  Intimate relationship stress may reduce risk of a ≥2 cm breast cancer. Suppression by stress of estrogen synthesis and metabolism is a possible mechanism.     

Inhibitory Effects of Crude α-Mangostin,a Xanthone Derivative,on Two Different Categories of Colon Preneoplastic Lesions Induced by 1, 2-dimethylhydrazine in the Rat

The purpose of this study was to examine whether crude á-mangostin (a major xanthone derivative in mangosteen ‍pericarp (Garcinia mangostana)) has short-term chemopreventive effects on putative preneoplastic lesions involved ‍in rat colon carcinogenesis. The crude preparation was obtained by simple recrystallization of an ethylacetate ‍extract of mangosteen pericarps. A total of 33 five-week-old male F344 rats were randomly divided into 5 experimental ‍groups. Rats in groups 1-3 were given a subcutaneous injection of 1,2-dimethylhydrazine (DMH)(40 mg/kg body ‍weight) once a week for 2 weeks. Starting one week before the first injection of DMH, rats in groups 2 and 3 were fed ‍a diet containing 0.02% and 0.05% crude á-mangostin, respectively, for 5 weeks. Rats in group 4 also received the ‍diet containing 0.05% crude á-mangostin, while rats in group 5 served as untreated controls. The experiment was ‍terminated 5 weeks after the start. Dietary administration of crude á-mangostin at both doses significantly inhibited ‍the induction and/or development of aberrant crypt foci (ACF) (P<0.05 for 0.02% crude á-mangostin, P<0.01 for ‍0.05% crude á-mangostin), when compared to the DMH-treated group (group 1). Moreover, treatment of rats with ‍0.05% crude á-mangostin significantly decreased dysplastic foci (DF) (P<0.05) and â-catenin accumulated crypts ‍(BCAC) (P<0.05), to below the group 1 values. The proliferating cell nuclear antigen (PCNA) labeling indices of ‍colon epithelium and focal lesions in groups 2 and 3 were also significantly lower than in group 1 and this effect ‍occurred in a dose dependent manner of the crude á-mangostin. This finding that crude á-mangostin has potent ‍chemopreventive effects in our short-term colon carcinogenesis bioassay system suggests that longer exposure might ‍result in suppression of tumor development. ‍     

Inhibition of NF-ĸB,Bcl-2 and COX-2 Gene Expression by an Extract of Eruca sativa Seeds during Rat Mammary Gland Carcinogenesis

The effect of Eruca sativa seed extract (SE) on nuclear factor kappa B (NF-κB), cyclooxygenase-2 (COX-2) and B-cell lymphoma-2 (Bcl-2) gene expression levels was investigated in rat mammary gland carcinogenesis induced by 7,12 dimethylbenz(α)anthracene (DMBA). DMBA increased NF-κB, COX-2 and Bcl-2 gene expression levels and lipid peroxidation (LP), while, decreased glutathione-S-transferase (GST) and superoxide dismutase (SOD) activities and total antioxidant concentration (TAC) compared to the control group. After DMBA administration, SE treatment reduced NF-κB, COX-2 and Bcl-2 gene expression levels and LP. Hence, SE treatment reduced inflammation and cell proliferation, while increasing apoptosis, GST and SOD activities and TAC. Analysis revealed that SE has high concentrations of total flavonoids, triterpenoids, alkaloids and polyphenolic compounds such as gallic, chlorogenic, caffeic, 3,4-dicaffeoyl quinic, 3,5-dicaffeoyl quinic, tannic, cinnamic acids, catechin and phloridzin. These findings indicate that SE may be considered a promising natural product from cruciferous vegetables against breast cancer, especially given its high antioxidant properties.     

First-in-Human Phase I Study of AC0010, a Mutant-Selective EGFR Inhibitor in Non–Small Cell Lung Cancer: Safety,Efficacy, and Potential Mechanism of Resistance

Introduction

AC0010 is a mutation-selective, third-generation EGFR tyrosine kinase inhibitor (TKI). This aim of this first-in-human phase I trial was to determine the maximum tolerated dose, recommended phase II dose, schedule, safety, pharmacokinetics, pharmacodynamics, and antitumor activity of AC0010 in patients with advanced or recurrent NSCLC and acquired resistance to a first-generation EGFR TKI.

The Effect of Helicobacter pylori Infection on hMSH2 and P53 Proteins in Gastric Carcinogenesis

OBJECTIVE To investigate the effect of Helicobacter pylori （H pylon） infection on expression of hMSH2 and P53 and its possible carcinogenic mechanism. METHODS H pylori infection was detected using a rapid urease test and haematoxylin and eosin （H＆E） staining. The hMSH2 and P53 proteins in gastric cancer （GC） tissue, its adjacent mucosa, gastritic mucosa and normal gastric mucosa were detected by the immunohistochemical SP method. RESULTS （1） The positive rate of hMSH2 expression in GC tissue （62.7%）was higher than those in non-cancer tissues （P〈0.001）; the positive rate of hMSH2 expression in poorly differentiated adenocarcinoma （76.4%） was higher than that in other carcinomas （P〈0.05）. The positive rate of P53 expression in GC tissue （51.9%） was higher than that in noncancer tissues （P〈0.001）; the positive rate of P53 expression in well-differentiated adenocarcinoma （32.6 %） was lower than that in other carcinomas （P〈0.01）. （2） The positive rate of hMSH2 expression in GC tissue with H pylori infection was lower than that without the infection （52.8% vs. 74.5%; P〈0.05）. The positive rate of P53 expression in GC tissue with H pylori infection was higher than that without the infection （61.4% vs. 40.6%; P〈0.05）.（3） The expression of hMSH2 and P53 in GC tissue correlated positively （r=0.457, P〈0.01）. CONCLUSION High expression of hMSH2 and P53 as well as their interaction may be involved in gastric carcinogenesis; H pylori infection affecting expression of hMSH2 and P53 may be one of its carcinogenic mechanisms.     

Management of Advanced Colon Cancer in a Community Hospital—Impact of Age on Clinical Management and Survival

Purpose  

Colon cancer is more common in the elderly than in younger and middle-aged people. Cancer clinical trials focus more on younger patients and the management of elderly patients with advanced disease is still unclear.     

Inhibitory Effects of Heated Garlic on N-Ethyl-Nี-nitro-N-nitrosoguanidine-induced Carcinogenesis in the Duodenum and Jejunum of C57BL/6 Mice

We examined the modifying effects of heated garlic (Allium sativum L.) on N-ethyl-N’-nitro-N-nitrosoguanidine ‍(ENNG)-induced duodenal and jejunal carcinogenesis in mice. Heated garlic powder used in this study was prepared ‍as follows: unpeeled garlic bulbs were blanched in boiling water for 6 min, and then peeled, the cloves being crushed, ‍homogenized, and finally freeze-dried. The garlic powder had almost undetectable alliinase activity and was rich in ‍alliin (the main sulfur compound of heated garlic; 22.1 mg/g dry weight). Male C57BL/6 mice were given ENNG ‍(100 mg/l) in drinking water for the first 4 weeks, and then basal diet (Group 1), or 10% (Group 2), 3% (Group 3) or ‍1% (Group 4) heated garlic in the diet for 30 weeks. At the termination of the experiment, the incidences of duodenal ‍tumors in Groups 1-3 were significantly lower than those in Group 1, and the multiplicities in Group 2 were significantly ‍lower than those in Group 1. Additionally, the incidences and/or multiplicities of the jejunal tumors in Groups 2 and ‍4 were also significantly lower than those in Group 1. In this study, we also examined changes in erythrocyte polyamine ‍levels. Values for Group 1 were significantly greater than those in the control group, and this elevation in Group 1 ‍were significantly inhibited by dietary heated garlic (10% in the diet; Group 2). These results indicated that the ‍post-initiation-stage feeding of heated garlic, especially at 10% in the diet, inhibits ENNG-induced duodenal and ‍jejunal carcinogenesis in mice.     

Ability of a Specific ERK Signal-Pathway Inhibitor to Reverse P-Glycoprotein- Mediated Vincristine Resistance in Colon Cancer Cell Unes

OBJECTIVE To investigate the effect of a specific inhibitor PD098059 of the extracellular-signal regulated protein kinase (ERK) pathway on the P-glycoprotein (P-gp)-mediated resistance of colon cancer cell lines SW480/VCR and CoLo205NCR.METHODS SW480NCR and CoLo205NCR cells were generated byexposuring SW480 and CoLo205 cells to vincristine (VCR) (30 ng/ml) for 72h, which resulted in a comparatively higher level of P-gp expression.Western blotting was used to analyze P-gp, MRP, LRP, GST-‘rr and TOPOIIexpression after exposuring the SW480 and CoLo205 cells to VCR (30 ng/ml)for 72 hrs. P-gp and pERK1/2 expressions was analyzed in SW480NCR andCoLo205/VCR cells treated with or without the specific inhibitor of MEK,PD098059. The MTT assay was used to determine the susceptibility ofSW480NCR and CoLo205NCR cells to VCR, treated with or withoutPD098059.I~F.SULI“S The results showed that VCR induced a comparatively higher levelof P-gp expression in the cell lines, but not that of MRP, LRP, GST-n- orTOPOII. P-gp expression levels were depressed significantly in SW480/VCR and COLO205/VCR cells by the specific inhibitor of MEK, PD098059.The IC50 (248 19.6 and 215 10.7 ng/ml) to VCR of SW480/VCR andCoLo205/VCR cells exhibited a 2.16 and 2.03-fold higher resistancecompared to the negative control group (SW480 and CoLo205 cells)(115 15.6 and 106 11.9 ng/ml), but a 1.35 and 1.21 -fold higher resistance thanthe group treated with VCR (30 ng/ml) PD098059 (184 21.8 and 177 19.4 ng/ml).CONCLUSION This study shows that the expression of P-gp can beinduced by exposuring cells to VCR, and that this induction can be reversedby inhibiting the ERK signaling pathway at the point of MEK by its specificinhibitor, PD098059. The ERK signal-transduction pathway may play a rolein modulating mdrl expression in colon cancer.     

Zebrafish as a "biosensor"? Effects of ionizing radiation and amifostine on embryonic viability and development

The zebrafish (Danio rerio) has emerged as a popular vertebrate model system for cancer and treatment-related research. Benefits include ease of care, rapid development, optical clarity of embryos, which allows visualization of major organ systems, and opportunities for genetic manipulation. However, specific parameters of radiation sensitivity have not been systematically documented. We investigated the effects of radiation and a radiomodifier on zebrafish viability and embryonic development. Embryos were exposed to gamma-radiation (5, 10, or 20 Gy) at sequential times postfertilization and serially assessed for viability and morphologic abnormalities. As expected, lethality and morphologic perturbations were more pronounced earlier in embryogenesis and with higher radiation doses and were partially reversed by amifostine. The effects of radiation and concurrent treatment with amifostine on the developmental organization of the eye and brain were striking. Radiation resulted in hypocellularity and disorganization of the cellular layers of the retina, effects partially reversed by amifostine, as well as lens opacification. Radiation strikingly reduced the volume of brain, but the volume loss was substantially blocked by amifostine. Increased terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling signal was noted in both the irradiated eye and brain, but reduced by amifostine. Finally, irradiating embryos resulted in caspase activation detectable in 96-well microplates, which was proportional to the number of embryos and radiation dose; the degree of activation was markedly reduced by amifostine. These results together suggest the power and versatility of the zebrafish in assessing the effects of radiation and radiomodifiers on organ and tissue development.     

Diclofenac, a selective COX-2 inhibitor, inhibits DMH-induced colon tumorigenesis through suppression of MCP-1, MIP-1α and VEGF

Angiogenesis is a physiological process involving growth of new blood vessels from pre-existing ones; however, it also plays a critical role in tumor progression. It favors the transition from hyperplasia to neoplasia, that is, from a state of cellular multiplication to uncontrolled proliferation. Therefore targeting angiogenesis will be profitable as a mechanism to inhibit tumor's lifeline. Further, it is important to understand the cross-communication between vascular endothelial growth factor (VEGF)-master switch in angiogenesis and other molecules in the neoplastic and pro-inflammatory milieu. We studied the role of two important chemokines [monocyte chemoattractant protein (MCP)-1 and macrophage inflammatory protein (MIP)-lα] alongwith VEGF and matrix metalloproteinases (MMPs) in non-steroidal anti-inflammatory drugs (NSAIDs)-induced chemopreventive effect in experimental colon cancer in rat. 1,2-Dimethylhydrazine (DMH, 30 mg/kg body weight, subcutaneously (s.c.) once-a-week) for 18 wk was used as pro-carcinogen and diclofenac (8 mg/kg body weight, orally daily) as the preferential cyclooxygenase-2 (COX-2) inhibitor. Expression of COX-2 and VEGF was found to be significantly elevated in the DMH-treated group as compared to the control, which was lowered notably by Diclofenac co-administration with DMH. Gelatin zymography showed prominent MMP-9 activity in the DMH-treated rats, while the activity was nearly absent in all the other groups. Expression of MCP-1 was found to be markedly increased whereas MIP-1α expression was found to be decreased in colonic mucosa from DMH-treated rats, which was reversed in the DMH + Diclofenac group. Our results indicate potential role of chemokines alongwith VEGF in angiogenesis in DMH-induced cancer and its chemoprevention with diclofenac.     

57. Effects of Light and Temperature on the Antimutigenicity of Chlorophyllin

Chlorophyllin (Sodium-Copper Salt, Chln), a derivative of chlorophyll, has been showed to be antimutagenic to certain chemical mutagens, carcinogens, and environmental mixes such as B(a)P, MNNG, AFB1, Trp-p-1, airborne particles, in many researches. But these results were obtained under common laboratory situation, that is to say, Chln was not treated with high temperature and/or exposed to light. In the     

Effects of β-lapachone, a new anticancer candidate, on cytochrome P450-mediated drug metabolism

Purpose

This study aimed to assess the potential inhibitory effects of β-lapachone, a new anticancer candidate, on the activities of the cytochrome P450 (CYP450) enzymes in vitro.

Methods

Different concentrations of β-lapachone were incubated with human liver microsomes in the presence of CYP isozyme-specific substrates and NADPH, and the formation of the marker metabolites was measured using liquid chromatography–tandem mass spectrometry. In addition, time-dependent inhibition was examined to characterize the mode of the inhibition.

Results

β-Lapachone showed concentration-dependent inhibitory effects on all CYP isozymes tested (CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYPC19, CYP2D6, and CYP3A4), and its half-maximal inhibitory concentration (IC₅₀) values ranged from 2.6 to 9.7 μM. However, β-lapachone did not appear to modulate CYP450 activities as a mechanism-based inactivator.

Conclusions

These results suggest that pharmacological drug–drug interactions might occur between β-lapachone and drugs co-administered with it, which are extensively metabolized by CYP450 enzymes, and thus, careful observation is required in clinical pharmacokinetic studies.     

Trends in classification,referral and treatment and the effect on outcome of patients with glioma: a 20 year cohort

This retrospective audit was conducted to examine the changes in patient characteristics, referral, treatment and outcome over a 20-year period in a large regional neuro-oncology centre, focusing on the impact of the changes in pathological classification of gliomas. Using the Edinburgh Cancer Centre (ECC) database all cases of glioma were identified and patient, tumour and treatment characteristics noted. Survival was calculated from date of surgery or, if no operation was performed, the date of referral. Comparison was made between four periods 1988–1992 (c1), 1993–1997(c2), 1998–2002(c3) and 2003–2007 (c4). During the 20 years, 1175 patients with a glioma were referred to ECC. The median age increased from 53 years to 57 years (p < 0.001) but the proportion without pathology remained unchanged (10%). The distribution of pathological grades changed over time Grade I–II: 24, 6, 6, and 6%, Grade III: 42, 27, 17, and 13% and Grade IV: 24, 61, 68, and 68% in c1, c2, c3 and c4, respectively (p < 0.001). Immediate RT was given to 68% (c1), 70% (c2), 78% (c3) and 79% (c4). Median interval from resection to RT reduced from 43 days (c1) to 36 days (c4) (p < 0.001). 5-year overall survival for patients with Grade III lesions increased: 21% (c1), 35% (c2), 37% (c3), 33% (c4) as did 1-year overall survival for Grade IV lesions: 18% (c1), 26% (c2), 29% (c3), 27% (c4)). This improvement probably reflects the change in pathological classification rather than a change in management. Proportional hazards analysis of grade IV 1993–2007 only (to reduce pathological variation) showed that younger age, frontal lesions, excision, higher RT dose had reduced hazard of death. Interval from surgery to RT had no impact on survival in this series.     

Potential of a COX-2 inhibitor in lowering ：hemotherapy-induced neutropenia

Objective This study was initially designed to evaluate the effect of celecoxib on the regimen of 5-fluorouracil,epirubicin,and cyclophosphamide（FEC）combination,followed by docetaxel（T）in neoadjuvant setting.An unplanned preliminary review on safety was conducted after a halt of the study due to the concerned potential cardiovascular risk of using COX-2 inhibitors.Methods We studied 23 consecutive cases of operable breast cancer having received four cycles of FEC（500 mg/m2,100 mg/m2,500 mg/m2）followed by four cycles of T（100 mg/m2）with concurrent celecoxib（400 mg twice daily）（group A）or same chemotherapy regimen but without concurrent celecoxib（group B）.These combined chemotherapies were administered every 3 weeks.The Chi-square test or Fisher＇s exact test were used to assess the difference in incidence of limiting hematological toxicites between groups.Results 23 patients（group A：n=12;group B,n=11）received a total of 183 out of 184 planned treatment cycles;one（4%,1/23）of them omitted the fourth cycle of FEC owing to repeated incidences of febrile neutropenia.Received dose intensity（RDI）for FEC in group A（90%±11%）was higher than that in group B（80%±8%）while RDI for T was similar between group A（93%±8%）and group B（96%±9%）.Of the first 91 treatment cycles of FEC,limiting hematological toxicity,severe neutropenia including febrile neutropenia,was significantly different between group A and B [（10.4%,5/48）vs.（32.6%,14/43）,P=0.009].Other toxicities commonly observed in chemotherapy receiving patients were manageable.Conclusions Neoadjuvant use of FEC followed by T with concurrent celecoxib appeared to be safe for treatment of operable invasive breast cancer.The observed lower incidence of chemotherapy-induced neutropenia is possibly contributed by the administration of COX-inhibitor.We believe that further investigation might provide more evidence on the use of COX-2 inhibitors in breast cancer.     

Unique antineoplastic profile of Saquinavir-NO, a novel NO-derivative of the protease inhibitor Saquinavir, on the in vitro and in vivo tumor formation of A375 human melanoma cells

We have recently shown that covalent attachment of the nitric oxide (NO) moiety to the HIV protease inhibitor Saquinavir (Saq) produced a qualitatively new chemical entity, named Saquinavir-NO (Saq-NO), with enhanced anticancer properties and reduced toxicity both in?vitro and in?vivo. The aim of this study was to address several unanswered questions both on the pharmacological profile of Saq-NO as well as on the in?vivo role of NO in the oncogenesis of A375 human melanoma cells. To this end, we have evaluated here the impact of single and combined effects of Saq-NO, Saq, the NO-donor DETA NONOate and the iNOS inhibitor L-NAME on the in?vitro as well as in?vivo growth of the iNOS positive A375 cells. Our data confirm clear-cut evidence for a strong and powerful anti-melanoma action of Saq-NO that is not duplicable by the combined use of Saq and DETA NONOate. Surprisingly, but also in agreement with the complex and multifaceted role of endogenous NO in A375 cells, both DETA NONOate and L-NAME significantly suppressed the in?vivo growth of xenotransplants.