Background: Inflammation, if uncontrolled, can promote the formation of colon cancer. Intestinal lymphocytes (IL) are immune cells that can participate in inflammation through the generation of cytokines and by causing direct cellular injury. Apoptosis, or programmed cell death, regulates the population of lymphocytes and dysregulation of this process results in the prolonged activation of IL that occurs during inflammation. Therefore, inducing apoptosis of IL is a viable mechanism by which inflammation and possibly colon carcinogenesis could be prevented. Experimentally, inflammation may be induced in mice by: 1) the addition of the chemical irritant dextran sulfate sodium (DSS) to drinking water or 2) exposure to acute exercise (AE; intense treadmill running). Bovine lactoferrin (bLf) is a dietary whey protein with demonstrated ability to promote anti-inflammatory responses by reducing pro-inflammatory or increasing anti-inflammatory cytokine concentrations within the intestine. There are also reports that bLf can alter apoptotic proteins in the intestinal epithelium to favour cell death. Moreover, athletes have been reported to supplement their diets with whey protein; it is also known clinically that after heavy competition some athletes may experience gastrointestinal distress. The role, however, of bLf in reducing inflammation by initiation of apoptosis or alteration of cytokine levels in IL has not been examined. Objectives: The primary objective of this research was to determine whether dietary bLf affects mouse IL apoptosis and cytokine concentrations in: 1) a normal, non-inflamed state, 2) following AE challenge and 3) following DSS treatment. A second objective was to directly examine the potential protective effects of dietary bLf from inflammatory damage caused by DSS and AE challenge when administered alone or in combination with a carcinogen. Methods: A total of 252 female C57BL/6 mice were used in the experiments. Apoptotic proteins (Bcl-2, caspase 3, Bax, cytochrome c), inflammatory cytokine proteins (TNF-α and IL-10) and a transcription factor for pro-inflammatory cytokines (NFκB) were determined in isolated mouse IL by Western blot analysis. Flow cytometry was used to determine the extent of apoptosis in mouse IL subsets by measuring phosphatidylserine surface expression using Annexin V+ (ANN+) and propidium iodide staining. Tissue inflammation was determined by histology (H&E staining) on segments of mouse small and large intestine. Diets were prepared and pelletted to contain 20% total protein and contained either bLf or were the control formulation (no bLf). Mice were exposed to bLf containing diets for 4 d or 12 d prior to sacrifice. DSS was provided at 5% in the drinking water for 4 consecutive days prior to sacrifice. Animals were subjected to three repeated bouts of AE (each separated by 24 h rest) involving treadmill running and sacrificed either immediately or 24 h after the final exercise bout. In the experiment involving carcinogenesis, mice were given two subcutaneous injections of azoxymethane (AOM), followed by a two week incubation period, and subsequently exposed to bLf or the control diet. Results: Results from the first experiment determined that 2.0% bLf was effective at reducing mouse IL levels of TNF-α (p<0.05) (pro-inflammatory) and increasing the percentage of apoptotic CD4+ IL (CD4+/ANN+, p<0.05) in healthy mice. Thus, 2.0% bLf was used for the subsequent experiments. Dietary bLf administration in mice exposed to AE was associated with lower levels in mouse IL of the anti-apoptotic protein Bcl-2 (p<0.01) and of TNF-α (p<0.05) and NFκB (p<0.05), both pro-inflammatory proteins. Further, the exercise protocol resulted in oxidative stress, as measured by 8-iso prostaglandin F2α levels in plasma, but did not induce intestinal inflammation, evident by the absence of both tissue damage and infiltration of immune cells. Following DSS treatment, mice supplemented with bLf enriched diets had lower levels of both TNF-α (non-significant, 34% reduction) and NFκB (p<0.05) and increased concentrations (p<0.01) of cytochrome c, a mitochondrial protein associated with cell death. DSS exposure in mice resulted in gross morphological alterations and infiltration of immune cells in the small and large intestine; these changes in tissue histology were not affected by the addition of bLf. Mice injected with AOM and then subjected to DSS, but not AE, had increased numbers (p<0.001) of aberrant crypts, preneoplastic colonic lesions, compared to animals only receiving AOM injection. Dietary bLf did not affect any of these carcinogenic processes. Conclusions: Collectively, these results suggest that dietary bLf administration reduces pro-inflammatory cytokine levels and has limited effects on apoptosis of mouse IL. Moreover, these modifying effects of bLf did not result in mucosal protection, as evident in the inability of this protein to reduce DSS-induced tissue damage or formation of aberrant crypts. Physiological and Clinical Implications: Although the long term physiological consequences of bLf supplementation in the regulation of intestinal immune homeostasis require further study, the following clinical implications are tentatively suggested by the findings from this thesis research. First, dietary bLf supplementation does not provide direct protection of the intestine during inflammation either with or without exposure to the carcinogen (i.e., AOM); hence, bLf (at least in the dietary concentration and exposure used in these experiments) may not be useful in reducing the formation of aberrant crypts and carcinogenesis. Second, dietary bLf should not be recommended as a supplement at this time for athletes experiencing intestinal distress since it had no impact on tissue indicators of disease in a model (DSS) shown to produce extensive inflammation and tissue pathology. Nonetheless, the findings raise the possibility that bLf can modify both cytokines and apoptotic protein expression in IL and may influence some aspects of inflammatory processes in the gut.

Diverse extracellular stimuli, including ultraviolet light, irradiation, heat shock, proinflammatory cytokines, trigger activation of MAPK pathway through phosphorylation on a TGY motif within the kinase activation loop. Protein MAPK appears to play a major role in apoptosis. It has been causally implicated in sepsis and arthritis. The translational small ubiquitin related modifier (SUMO) modification of proteins has been shown to play multiple functional roles in several cellular processes, including signal transduction, protein targeting, stabilization, transcriptional activation and apoptosis. Our previous study demonstrated that the expression levels of SUMO-1 rnRNA and proteins were enhanced in Helicobacter pylori infected human gastric epithelial cells. The activation of MAPK pathway and cellular apoptosis of AGS cell lines were increased during Helicobacter pylori infection. It was hypothesized that Helicobacter pylori functioning as a biological stress that induced MAPK mediated apoptosis which may be regulated by sumoylation. Results showed that MAPK phosphorylation and cellular apoptosis were enhanced in RFP-SUMOs or GFP-MAPK expressing cells, especially during Helicobacter pylori infection. It was inhibited by pretreatment of MAPK inhibitor. The enhanced phosphorylation and apoptosis were observed during GFP-MAPK overexpression. It¡¦s suggested that MAPK is a target protein for SUMOs.

Hepatocellular carcinoma (HCC) or hepatoma is the fifth most common cancer and the third most common cause of cancer-related deaths worldwide. Early detection of HCC still remains challenge. Patients with late-stage HCCs have very limited therapeutic options and relatively poor prognosis. Therefore, recognition of useful tumor marker for the diagnosis of HCC may aid in the management with this lethal malignancy, and designing effective therapies. In our previous study, through in silico data mining of numerous available cDNA microarray databases, the CDC28 protein kinase regulatory subunit 1B (CKS1B) transcript was found to be frequently upregulated in HCCs and the gene is strongly associated in clinical aggressiveness. Moreover, gain of chromosome 1q copy is one of the most frequently detected alterations in HCC and 1q21 is the most frequent minimal amplifying region. Mammalian CKS1B gene, a member of the highly conserved cyclin kinase subunit 1 protein family, mapped to 1q21.2-q22, which interacts with cyclin-dependent kinases and frequently up-regulated in human HCC specimens, and this gene also has been reported to play oncogenic roles in other human cancers. Furthermore, this gene was identified as an essential cofactor of S-phase kinase-associated protein 2 (SKP2) in the SKP2-containing SKP1-Cullin1-F-box ubiquitin ligase complex¡Vmediated ubiquitination of the cell cycle inhibitor protein cyclin-dependent kinases 1A (p27kip1) that leads to the proteasomal degradation of p27kip1. In the present study, our results indicate that CKS1B overexpression may contribute to hepatocarcinogenesis by enhancing the cellular tumorigenic potential. In addition, CKS1B was correlated with the HCC-derived cells proliferation, and CKS1B knockdown significantly inhibited the tumorigenic potential of HCC-derived cells. In this study, we examined that CKS1B knockdown and overexpressed in HCC cells significantly changed the expression of genes known to participate in various cellular processes, including, apoptosis, cell cycle, proliferation, viability, invasion, and migration, implying that CKS1B may play considerable and diverse roles in hepatocarcinogenesis.

In the studies described in this dissertation, we investigated the roles of p53 in normal development, teratogen-induced apoptosis, and birth defects. In the first study, the activation of p53 and its target genes, p21, NOXA, and PUMA, were examined during neural tube closure in mouse embryos exposed to hyperthermia (HS) or 4- peroxycyclophosphamide (4CP), teratogens known to induce neural tube defects (NTDs). In the second study, using p53-deficient mice, we examined the expression of mRNAs and microRNAs (miRNAs) during neural tube closure. In the third study, the incidence of NTDs was investigated in p53- and p21-deficient mouse embryos exposed to HS. Finally, we examined the induction of apoptosis in p53-deficient mouse embryos exposed to HS. HS and 4CP induced the activation of p53 by phosphorylation and accumulation of the protein, leading to an increase in p21 proteins and mRNAs. Although HS and 4CP also induced the expression of Noxa and Puma mRNAs, no significant increases in NOXA and PUMA proteins were observed, suggesting a possible role of transcriptionindependent apoptosis. In the second study, we showed that the expression of 388 genes and 5 miRNAs were significantly altered in p53 -/- compared to p53 +/+ embryos. Finally, we showed that 10% of p53 -/- pups exhibit exencephaly, spina bifida, and/or preaxial polydactyly, whereas no malformations were observed among p21 -/- offspring in the absence of HS. HS resulted in an increased incidence of exencephaly in both p53 and p21 null mice indicating that these two proteins act as teratogen suppressors. Our preliminary data additionally showed that a decreased level of apoptosis was observed in HS-treated embryos lacking a p53 allele, suggesting that too little apoptosis may be causally linked to NTDs observed in embryos exposed to HS. Taken together, these studies suggest that precise control of apoptosis and cell cycle arrest pathways are critical for neural tube development and the prevention of teratogen-induced NTDs.

Apoptolidin 1.1 was isolated in 1997 by Hayakawa and co-workers from a soil bacterium Nocardiopsis sp. during screening for specific apoptosis inducers. The primary biological test revealed that this polyketide macrolide induced apoptosis in cells transformed with the adenovirus type E1A oncognene, but not normal cells. This dissertation describes the latest studies in understanding of apoptolidin’s biological activity mechanism and previous contributions towards its total synthesis. Synthesizing apoptolidinone 1.26 by an intra-molecular Horner-Wadsworth-Emmons approach featuring a Suzuki coupling, cross metathesis and two diastereoselective aldol reactions is discussed. 15 mg apoptolidinone is prepared via our previously developed intramolecular Suzuking coupling approach. Ammocidin 3.1, which was found to induce apoptosis in Ba/F3-v12 cells in an IL- 3 free medium, is a specific apoptosis inducer discovered by Hayakawa and co-workers in 2001 from Saccharothrix sp. AJ9571. A strategy featuring Suzuki coupling, cross metathesis, Yamaguchi macrolactonization and three asymmetric aldol reactions was applied to the total synthesis of ammocidinone 3.6, the aglycone of ammocidin. The preparation of the key building blocks was discussed in the following chapter: aldehyde 3.8 (C14-C19) was synthesized via Sharpless asymmetric epoxidation; ethyl ketone 3.9’ (C20-C28) was prepared via Kobayashi and Crimmins’s asymmetric aldol methodologies; aldehyde 3.14 (C7-C13) was generated by Brown crotylation and cross metathesis.

Cancer has become the major factor causing death in Taiwan. Although brain tumor take a few ratio in cancer, the current therapy shown not effect well. In previous studies, EGCG will promote cancer cells to go apoptosis after treatment with EGCG. But the mechanism in brain tumor is unknown. So, we use EGCG from green tea extract to investigate cell death of human brain tumor cell lines GBM8401, U87MG and U251. The metabolic rates of GBM8401, U87 and U251 are decrease with EGCG treatment, and it is significant in GBM8401. We also examine some genes and proteins related apoptosis by RT-PCR and Western blotting. The accumulation of p21, p27 and p53 are increasing with concentration and time course treatments. EGCG can inhibit the ability of brain tumor to form foci in anchorage-independent growth assay. Our data show that EGCG can inhibit brain tumor cell lines GBM8401, U87 and U251. It is validated that EGCG has the potential of cancer therapy and prevention.

One of the physiological functions of apoptosis is to eliminate cells that have sustained genetic aberrations, thereby preventing damaged cell from attaining uncontrolled cell proliferation or transformation into carcinoma. The apoptotic response is mediated by many apoptotic genes including Fas, survivin, caspases etc. through either the extrinsic pathway (death receptor pathway) or the intrinsic pathway (mitochondrial pathway). In this dissertation, we carried out a hospital-based case-control study to investigate the association between seven Fas related apoptosis pathway genes (Fas, FasL, survivin, XIAP, caspase-3, caspase-8 and caspase-9) and the risk for oral squamous cell carcinoma (OSCC). In this study, 279 newly diagnosed OSCC patients and 469 frequency-matched controls were recruited at Kaohsiung Veterans General Hospital from 2003 to 2006. Total eight various polymorphisms in seven genes mentioned above were examined by PCR-RFLP and our results showed that only FasL ¡V844TT genotype (P=0.047) was associated with the risk of OSCC. However, a trend of increased risk of OSCC was found in people with the increasing putative high-risk genotypes of Fas related apoptosis pathway genes (P for linear trend, 0.034). From our results of the gene-environment interaction analyses, three important observations were listed below: (1) the polymorphism of both FasL T-844C and survivin codon Lys129Glu were risk factors for Fukienese (P=0.023 and P=0.014, respectively), but not for other ethnicities examined. (2) For non-smokers, survivin codon Lys129Glu and caspase-3 A21926C polymorphisms had significant protect (P=0.047 and P=0.024, respectively). (3) For betel quid (BQ) chewers, caspase-9 codon Arg221Gln polymorphism was an important risk factor (P=0.048). Together, the results suggested that gene polymorphisms of Fas related apoptosis pathway were associated with the risk of OSCC. In order to evaluate the relationship between p53 and caspase-3 protein expression levels or clinicopathologic characteristics and survival outcome in OSCC, we examined the protein expression profilings of caspase-3 and p53 in those patients with buccal mucosa squamous cell carcinoma (BMSCC). Total 117 primary buccal carcinoma specimens were collected at KSVGH between 1990 and 2005 and their paraffin-embedded tissues were sectioned and subjected for immunohistochemistry examination. The overall cumulative survival rate was 62% for 5-years, 39% for 10-years and 18% for 14-years, respectively. Ours results showed that the survival rate of BMSCC was significantly correlated with all clinicopathological characteristics including cell differentiation, pathological stage, tumor size, lymph node metastasis, post-operative RT, post-operative CT and BQ chewing status. Most importantly, the high caspase-3 protein level in cytoplasm was an unfavorable prognostic factor in the univariate or the multivariate analysis. In conclusion, the join effect of genetic polymorphisms of Fas related apoptosis pathway genes and gene-environment combined effect may play important roles in the OSCC risk. In addition, high caspase-3 protein expression in cytoplasm may be used as a prognostic marker for patients with BMSCC.

Aging is characterized by a progressive decline in cardiac function. A critical contributor to the age-related impairment in heart function is the loss of cardiac myocytes through ??apoptosis??, or programmed cell death. A dramatic increase in the rate of apoptosis has been reported with aging in the rat left ventricle. In contrast, exercise training not only improves cardiac function, but also reduces the risk of heart disease. However, the ability of exercise training to modulate apoptotic signaling and apoptosis in the aging heart remains unknown. Therefore, the purpose of this study was to determine the effects of exercise training on apoptotic signaling and apoptosis in the aging heart. We hypothesized that (1) aging would increase pro-apoptotic signaling and apoptosis in the rat left ventricle, and (2) exercise training would ameliorate upregulation of Bcl-2 family-driven apoptosis in the heart. Four and 25 month old Fischer-344 rats were assigned to four groups: young control (YC), young trained (YT), old control (OC), and old trained (OT). Exercise training groups ran on a treadmill for 60 min/day at 15 m/min (15&#730; incline), 5 d/wk for 12 wk. Protein expression of Bax, Bcl-2, caspase-9, and cleaved caspase-3 was measured using Western immunoblot analysis. Apoptosis (DNA fragmentation) was assessed using a cell death detection ELISA. Bax levels in OC were dramatically higher (+176.0%) compared to YC. In contrast, exercise training resulted in a significant decrease (-53.4%) in Bax in OT compared to OC. Bcl-2 levels in OC were lower (-26.3%) compared to YC. Conversely, exercise training significantly increased Bcl-2 levels by 117.8% in OT compared to OC. Caspase-9 levels were higher (+98.7%) in OC than YC, while exercise training significantly reduced caspase-9 levels in YT (-52.6%) and OT (-76.9%), respectively. Aging resulted in a dramatic increase (+122.8%) in cleaved caspase-3 levels and a significant decrease (-32.9%) with exercise training. Finally, apoptosis (DNA fragmentation) significantly increased (+163.8%) with aging and decreased (-43.9%) with exercise training. These novel data indicate that aging increases pro-apoptotic signaling and apoptosis in the left ventricle, while exercise training is effective in diminishing pro-apoptotic signaling and apoptosis in the aging heart.

Helicobacter pylori (H. pylori) causes peptic ulcer or gastric cancer through different virulence factors including lipopolysaccharides (LPS), the cytotoxin-associated gene A product (CagA), and vacuolating cytotoxin A (VacA) etc. It stimulated mitogen-activated protein (MAP) kinase signaling cascades. Small ubiquitin-related modifier (SUMO) is a member of ubiquitin-related protein modifiers. However, the mechanisms of the involvement of SUMO-1 on H. pylori induced apoptosis were not clear. Our previous study showed that the expression of RFP-SUMO-1 and apoptosis were increased significantly by fluorescence microscopy assays on RFP-SUMO-1 transfectants during H. pylori infection. In addition, the cytoplasmic SUMO-1 was increased during infection and positively associated with apoptosis. Here, how SUMO-1 was involved in the apoptotic signaling enhancement during H. pylori infection was studied. Results showed that H. pylori infection enhanced MAP kinase activation and the effects were stronger on the SUMO-1 overexpressed cells. However, it was not affected by the secretion of CagA or VacA toxins of H. pylori. To investigate the possible role of SUMO-1 on MAPKs mediated signaling pathways, three selective MAPKs inhibitors were used on RFP-SUMO-1 overexpressed cells. Only p38 inhibitor decreased the levels of apoptosis during H. pylori infection and the expression of p53 was increased on RFP-SUMO-1 1 overexpressed cells. Thus, p38 and p53 pathways were suggested to be involved in SUMO-1 enhanced apoptosis during H. pylori infection. In addition, the nuclear localization of NF-£eB and expression of COX-2 were enhanced on RFP-SUMO-1 overexpressed cells. Moreover, more nuclear NF-£eB and cytoplasmic as well as nuclear RFP-SUMO-1 were observed during H. pylori infection. Our data suggest that H. pylori infection enhances SUMO-1 expression which activates MAPKs on both the pro-apoptotic p38-p53 pathway and the anti-apoptotic ERK-NF-£eB-COX2 pathway. The detail mechanisms on how cells making the final decision on the survival or apoptosis were still not clear and deserving to investigate.

Universiẗat, Diss.--Jena, 2007.