Deoxycholic acid (DCA) is a secondary bile acid postulated to be involved in the etiology and the progression of colorectal cancer, but its specific mechanisms are not fully understood. DCA has been shown to induce apoptosis allowing selection for apoptosis-resistant cells, which highlights the importance of understanding the mechanisms of action of DCA. Previously, it has been demonstrated that DCA perturbs the plasma membrane, leading to the activation of receptor tyrosine kinases. Because the insulin-like growth factor-1 receptor (IGF-IR), a receptor tyrosine kinase, is demonstrated to play a significant role in protecting colorectal cancer cells from apoptosis, we hypothesized that DCA modulates IGF-IR functions in colorectal cancer cells. We demonstrated that DCA induced the dynamin-dependent endocytosis of IGF-IR through both clathrin-mediated and caveolin-1-dependent mechanisms. Endocytosis of IGF-IR sensitized cells to DCA-induced apoptosis, which demonstrated that IGF-IR played a role in protecting cells against DCA-induced apoptosis. Since DCA-induced endocytosis of IGF-IR was determined to be a caveolin-1 dependent process, caveolin-1 knockdown in HCT116 (HCT116-Cav1-AS) prevented the DCA-mediated endocytosis of IGF-IR. However, we observed an increased sensitivity of DCA-induced apoptosis in the Cav1-AS cells. This suggested that caveolin-1 knockdown altered the plasma membrane dynamics such that although IGF-IR was maintained at the plasma membrane, it facilitated a pro-apoptotic signal. We demonstrated that DCA induced the activation of the pro-apoptotic p38 signaling pathway in HCT116-Cav1-AS, but not in HCT116-Mock, via IGF-IR. Inhibition of both the IGF-IR and p38 independently in HCT116-Cav1-AS significantly decreased their sensitivity to DCA-induced apoptosis. These observations demonstrated that, in a caveolin-1 dependent manner, IGF-IR played a dynamic role in the DCA-mediated apoptosis. Finally, we provided preliminary evidence demonstrating that autophagy played a central role in protecting DCA-resistant cells from DCA-induced apoptosis.Since resistance to DCA also confers apoptosis-resistance, understanding the mechanisms that lead to or prevent DCA-induced cell death is significant, since they can lead to the development of novel therapeutic strategies to sensitize apoptosis-resistant colorectal cancer cells to undergo cell death.

Introduction: Colon cancer is the third leading cause of cancer death among women in Canada. Although regular screening beginning at age 50 years can significantly decrease risk of colon cancer mortality, many eligible Canadian women have never obtained screening. Cancer screening rates among immigrant women to Canada are even lower than for native-born women. Disparities in the use of preventive cancer services by immigrants have been linked to limited acculturation and speaking a language other than English. Poor prose comprehension may frustrate access and use of preventive cancer information by older ESL immigrant women to Canada. In order to develop useful and actionable cancer prevention information, it is necessary to understand the barriers ESL immigrant women face in obtaining and using health and cancer information. Therefore, the primary objective of this research was to assess the relationship of acculturation on the prose comprehension of older ESL immigrant women to Canada. Methods: Interviews were conducted with 78 older adult Spanish-speaking immigrant women (aged 45 to 73 years) residing in Kitchener-Waterloo, Ontario. Acculturation was inferred by length of Canadian residency and measured using the Bidimensional Acculturation Scale (BAS). Several measures were used to assess comprehension including the shortened Test of Functional Health Literacy in Adults (S-TOFHLA), the Rapid Estimate of Literacy in Medicine (REALM), the Newest Vital Sign (NVS), and a modified Cloze procedure. The modified Cloze procedure was constructed using a one-page colon cancer information sheet created for the public by the Canadian Cancer Society. Four multiple linear regression analyses were used to test the relationship between the independent variables of acculturation (BAS) and length of Canadian residency, age, Spanish language education, employment, and media variables (television and internet use) on each measure of prose comprehension (i.e., dependent variables of scores on S-TOFHLA, NVS, REALM and Cloze). Logistic regression was used to test whether acculturation and comprehension predicted screening intentions. Semi-structured interviews were conducted to identify the women’s cancer information needs and preferences as well as the barriers they experienced in obtaining and understanding English language cancer information. Results: Three significant models predicting comprehension of colon cancer and health information were identified. The independent variables BAS, Spanish language education and television viewing explained 23% of the variation in Cloze comprehension scores (F=6.76; df=3; p < 0.01; R2= 0.23). Approximately 42% of the variation in S-TOFHLA scores among older ESL immigrant women was explained by the independent variables BAS, age, television viewing and internet use (F=12.13; df=5; p < 0.01; R2=0.42). Using REALM as the dependent measure of comprehension, BAS and television viewing explained 17% of the variation in scores (F=7.54; df=2; p<0.01; R2=0.17). BAS was the only significant predictor of the dependent comprehension measure NVS (F=5.36; df=1; p=0.02; R2=0.07). Logistic regression models predicting colon cancer screening intentions were not significant. Qualitative data analyses revealed that women’s colon cancer information needs, preferences and perceived barriers accessing English language information did not vary according to BAS score or duration of residency in Canada. All women requested actionable information that was community and culturally specific. Additional factors related to older ESL immigrant women’s comprehension of cancer information were identified. These included self-efficacy, social networks and mode of information delivery. These additional modes of information delivery included receiving health information orally as compared to written information. Conclusion: Acculturation (as measured by BAS) significantly predicted prose comprehension by older ESL Spanish speaking immigrant women across four separate measurement tools (Cloze, S-TOFHLA, REALM, NVS). Yet, the proportion of the variance in comprehension scores explained by acculturation and other demographic variables was low to modest, ranging from 7-42%. In addition to acculturation, self-efficacy and social networks may also be associated with prose comprehension. Low self-efficacy among older ESL immigrant women may be a barrier to information seeking and perceived comprehension. However, strong social networks may provide women with the confidence and resources necessary to access health information and services. These results highlight the need for the additional research regarding the influence of self-efficacy on ESL immigrants’ ability to find and use health and cancer information. Recommendations: This research has important implications for public health educators. Health educators are encouraged to develop cancer and health information for ESL speakers in Canada that is community, culturally and linguistically specific and which provides actionable information. This is especially salient given the changing demographic and cultural profile of Canadians. Also, among older ESL immigrants who struggle with language barriers, receiving health information orally may be preferred.

This study investigated the antiviral, chemoprotective and proliferative effects of strawberry anthocyanins on herpes simplex virus type-1, cancerous cell lines HT-29 and AGS, and normal cell lines Hs 738.St/Int and CCD-18Co. Antiviral properties were measured by infecting vero cells from adult grivet (Cercopithecus aethiops) with herpes simplex virus type-1 (HSV-1) and treating with a concentration of 1.25-20 µg/mL of strawberry anthocyanins. Infectivity and replication were quantified for herpes simplex virus type-1 using the direct plaque assay and reporting PFU/mL. Strawberry anthocyanins (>20 µg/mL) inhibited the herpes simplex virus infectivity in vero cells by 100% (p<0.05). Strawberry anthocyanins at concentrations of 5, 10 and 20 μg/mL were reduced to 75.36, 57.98, and 31.46 percent of the control (100%) (p<0.05). Chemoprotective and proliferative effects of strawberry anthocyanins were analyzed for the human cell lines AGS, Hs 738.St/Int, HT-29, and CCD-18Co at a concentration of 25-200 µg/mL and quantified using the sulforhodamine-B assay. Growth inhibition occurred at a level of ≥87% for treatment concentrations 100 and 200 µg/mL for the cancerous AGS and HT-29 cell lines (p<0.0001). Proliferation rates for the normal Hs 738.St/Int and CCD-18Co cell lines increased at all treatment concentrations of 25-200 μg/mL (p<0.0001); suggestingthat the observed proliferative activity may be associated with anthocyanin treatment.Strawberry anthocyanin treatment concentration worked in a dose dependent manner for the HSV-1 and the cancerous AGS and HT-29 cells. The caspase-3 assay was performed to demonstrate potential mechanism of action and confirmed thatanthocyanin treatments play a role in apoptosisby the up regulation of caspase-3.Significantdifferences were seen between the growth characteristics of cancerous cell linescompared to their equivalent normal cell lines (p<0.0001). In summary, the antiviral findings suggest that strawberry anthocyanin extracts could be an effective topical treatment and/or prophylactic agent for oral herpetic infections (HSV-1). Also, the in vitro chemoprotective effect of strawberry anthocyanins found may be relevant to in vivo work in the future because when anthocyanins are consumed in the diet they come in direct contact with the gastrointestinal tract and may provide chemoprotection upon contact with the stomach and gastrointestinal tract’s epithelial cell layer.

OATP1B3 belongs to the OATP (organic anion transporting polypeptides) superfamily, responsible for mediating the transport of various endogenous and xenobiotic substrates. OATP1B3 was initially reported to be expressed exclusively in the hepatocytes where it mediates the uptake of numerous endogenous substrates (e.g. bile acids, steroid hormone conjugates) and several clinically relevant drugs including anticancer drugs. Later, a number of studies reported that OATP1B3 is also frequently expressed in multiple types of cancers and may be associated with differing clinical outcomes. However, a detailed investigation on the expression, localization and functions of OATP1B3 expressed in cancer has been lacking. In this thesis work, we confirmed that colon and pancreatic cancer cells express a cancer-specific OATP1B3 variant (csOATP1B3), different from OATP1B3 wild-type (WT) expressed in the normal liver. The csOATP1B3 utilizes an alternative transcription initiation site and the translated product of csOATP1B3 lacks the first 28 amino acids at the N-terminus of OATP1B3 WT. Our results show that csOATP1B3 has modest uptake transporter functions and reduced plasma membrane localization compared to OATP1B3 WT. In our efforts to investigate the regulatory mechanism underlying the expression of csOATP1B3, we found that hypoxia inducible factor-1α (HIF-1α) may play a key role in the regulation of csOATP1B3 in colon and pancreatic cancer cells. In a separate study, we tested whether the N-terminal sequence of OATP1B3 WT plays an important role in the membrane trafficking. This is based on the observation that csOATP1B3 lacking the first 28 amino acids at N-terminus of OATP1B3 WT displays a predominantly cytoplasmic localization pattern. Using the constructs with N-terminal truncations and point mutations, we verified that the N-terminus of OATP1B3 WT contains important motifs in its membrane trafficking. In particular, the amino acids within a putative β-turn-forming tetrapeptide appear to be important in regulating the membrane trafficking of OATP1B3 WT. The findings from this thesis work provide important insights into the functional and clinical significance of OATP1B3 in cancer and normal liver.

Objectives: The aim of this dissertation was to examine bias in randomized controlled trials (RCTs) and non-randomized studies (NRS) in surgery using the literature evaluating laparoscopy and conventional (i.e. open) surgery for the treatment of colon cancer as a case study. The objectives were 1) to develop a conceptual framework for bias in comparative NRS; 2) to compare effect estimates from NRS with those from RCTs at low risk of bias; 3) to explore the impact of NRS-design attributes on estimates of treatment effect. Methods: The methods included a modified framework synthesis, systematic review of the literature, random-effects meta-analyses, and frequentist and Bayesian meta-regression. The Cochrane Risk of Bias Tool was used to classify trials as Strong RCTs (i.e. low risk of bias) or Typical RCTs (i.e. unclear or high risk of bias). Results: A conceptual framework for bias in comparative NRS was developed and it contains 37 individual sources of bias or “items”. These items were organized within 6 overarching “domains”: selection bias, information bias, performance bias, detection bias, attrition bias, and selective reporting bias. Our analyses revealed that NRS were associated with more extreme estimates of benefit for laparoscopy than Strong RCTs when examining subjective outcomes. The odds ratios from NRS were 36% smaller (i.e. demonstrating more benefit for laparoscopy) than those from Strong RCTs for the outcome post-operative complications (Ratio of Odds Ratios, ROR 0.64, [0.42, 0.97], p=0.04). Similar exaggerated benefit was seen among NRS when assessing length of stay, (Difference in Mean Differences, -2.15 days, [-4.08, -0.21], p=0.03). This pattern was not observed with the objective outcomes peri-operative mortality and number of lymph nodes harvested. Analyses adjusted for period effects and between-study case-mix yielded similar findings. Finally, effect estimates in NRS did not consistently vary according to the presence or absence of nine design characteristics identified from the conceptual framework. Conclusions: We have demonstrated that the results of surgical NRS can be significantly biased as compared with those of low risk of bias RCTs when evaluating subjective outcomes. However, none of the nine NRS-design characteristics examined was consistently associated with biased effect estimates.

Objectives: The aim of this dissertation was to examine bias in randomized controlled trials (RCTs) and non-randomized studies (NRS) in surgery using the literature evaluating laparoscopy and conventional (i.e. open) surgery for the treatment of colon cancer as a case study. The objectives were 1) to develop a conceptual framework for bias in comparative NRS; 2) to compare effect estimates from NRS with those from RCTs at low risk of bias; 3) to explore the impact of NRS-design attributes on estimates of treatment effect. Methods: The methods included a modified framework synthesis, systematic review of the literature, random-effects meta-analyses, and frequentist and Bayesian meta-regression. The Cochrane Risk of Bias Tool was used to classify trials as Strong RCTs (i.e. low risk of bias) or Typical RCTs (i.e. unclear or high risk of bias). Results: A conceptual framework for bias in comparative NRS was developed and it contains 37 individual sources of bias or “items”. These items were organized within 6 overarching “domains”: selection bias, information bias, performance bias, detection bias, attrition bias, and selective reporting bias. Our analyses revealed that NRS were associated with more extreme estimates of benefit for laparoscopy than Strong RCTs when examining subjective outcomes. The odds ratios from NRS were 36% smaller (i.e. demonstrating more benefit for laparoscopy) than those from Strong RCTs for the outcome post-operative complications (Ratio of Odds Ratios, ROR 0.64, [0.42, 0.97], p=0.04). Similar exaggerated benefit was seen among NRS when assessing length of stay, (Difference in Mean Differences, -2.15 days, [-4.08, -0.21], p=0.03). This pattern was not observed with the objective outcomes peri-operative mortality and number of lymph nodes harvested. Analyses adjusted for period effects and between-study case-mix yielded similar findings. Finally, effect estimates in NRS did not consistently vary according to the presence or absence of nine design characteristics identified from the conceptual framework. Conclusions: We have demonstrated that the results of surgical NRS can be significantly biased as compared with those of low risk of bias RCTs when evaluating subjective outcomes. However, none of the nine NRS-design characteristics examined was consistently associated with biased effect estimates.

About half of million deaths caused by colorectal cancer (CRC) has been reported worldwide every year. Programmes for early diagnosis of CRC has reduced mortality due to this disease, as the cancer is diagnosed in earlier stages which can be treated more successfully. Programme for early CRC diagnosis in Lithuania has been based on the faeces occult blood test (FOBT). If positive FOBT result is obtained, patients should be referred for colonoscopy (CS) examination. Based on the data from the National Health Fund, during the first three years CS examination was carried out for a little bit more than half of the patients participating in the programme and presenting with positive FOBT result. Aiming to improve accuracy of CRC diagnostics we have suggested alternative CS examination – computed tomography colonography (CTC). The aim of our study was to establish diagnostic value of CTC examination in the identification of neoplastic alterations in the patients with positive FOBT result and to specify factors having influence on the examination quality. CTC examinations were carried out and their results were compared with the findings of CS. We discovered that CTC is of high diagnostic value for detection of lesions sized ≥ 6 mm and of very high diagnostic value for detection of large ( ≥ 10 mm) polyps in a colon. We found out that the length of colon had no influence on how patients tolerated this examination and on patients well-being during CTC procedure, and colon cleaning... [to full text] / Pasaulyje kasmet nuo storosios žarnos vėžio (SŽV) miršta apie pusė milijono žmonių. SŽV ankstyvosios diagnostikos programos sumažina mirtingumą nuo šios ligos, nes vėžys tada yra aptinkamas anksčiau ir galima jį lengviau išgydyti. Lietuvoje SŽV ankstyvosios diagnostikos programa yra paremta slapto kraujo išmatose nustatymo testu (FOBT). Po teigiamo FOBT atsakymo pacientai yra nukreipiami kolonoskopijai (KS). Valstybinės ligonių kasos duomenimis per pirmuosius trejus metus iš pacientų, dalyvavusių programoje, kuriems nustatytas teigiamas FOBT, iš jų tik kiek daugiau nei pusei pacientų atlikta KS. Norint dažniau diagnozuoti SŽV, pasiūlėme alternatyvų KS tyrimą - kompiuterinės tomografijos kolonografiją (KTK). Taikydami KTK ir lygindami jos rezultatus su KS, norėjome išsiaiškinti KTK tyrimo diagnostinę vertę nustatant neoplastinius pakitimus pacientams su teigiamu FOBT bei nustatyti tyrimo kokybei darančius įtaką faktorius. Nustatėme, kad KTK pasižymi didele diagnostine verte nustatant ≥6 mm dydžio pakitimus bei labai didele diagnostine verte nustatant didelius (≥10 mm) polipus, storojoje žarnoje. Nustatėme, kad storosios žarnos ilgis neturi įtakos KTK tyrimo tolerancijai ir paciento savijautai KTK metu, o žarnos išsivalymo kokybė prieš KTK tyrimą nepriklauso nuo anatominių storosios žarnos savybių – tokių, kaip ilgis. Išsiaiškinome, kad KTK tyrimas yra jautrus nustatant storosios žarnos neoplastines adenomas ir vėžį, bet nesiekia KS tyrimo jautrumo, todėl KTK taikyti... [toliau žr. visą tekstą]

Darbo tikslas: ištirti pacientų, dalyvaujančių profilaktinėje storosios žarnos vėžio patikroje, pasitenkinimą endoskopiniu tyrimu. Tyrimo uždaviniai: 1. Įvertinti profilaktinėje storosios žarnos vėžio patikroje dalyvaujančių pacientų informuotumą apie atliekamą tyrimą. 2. Nustatyti veiksnius, lemiančius pacientų, dalyvaujančių profilaktinėje storosios žarnos vėžio patikroje, žarnyno paruošimo kokybę. 3. Įvertinti veiksnius, lemiančius pacientų pasitenkinimą endoskopinio tyrimo metu. Tyrimo kontingentas ir metodai. 2013 metų kovo – gruodžio mėnesiais atlikta anoniminė anketinė apklausa. Tyrime dalyvavo (42,4 proc. vyrų ir 57,6 proc. moterų) pacientai, kurie tyrimo laikotarpiu buvo siųsti į Lietuvos Sveikatos Mokslų universiteto ligoninės Kauno klinikų Endoskopijų skyrių atlikti endoskopinio storosios žarnos tyrimo (n=177, atsako dažnis - 93,1 proc.). Tyrimui naudota autorės sukurta anketa, remiantis analizuota Lietuvos ir užsienio šalių moksline literatūra. / Research aim: to research patients satifaction during screening colonoscopy procedure. The research goals: 1. To evaluate patients, participating in colon cancer prevention screening programme, awareness of the administered colonoscopy procedure. 2. To determine factors, influencing patients, participating in colon cancer prevention screening programme, quality of bowel preparation. 3. To evaluate factors, determining the patients satisfaction during colonoscopy procedure. Research contingent and methods. During March to December 2013 an anonymous questionnaire was conducted of 177 participants (response rate – 93,1%), i.e. patients (42,4% men, 57,6 % women) administered to perform colonoscopy to Endoscopy department in hospital of Lithuanian University of Health Sciences Kaunas Clinics. A questionnaire, made by the author , based on the analysis of Lithuanian and foreign scientific literature, was applied for the research.

Hormone replacement therapy and estrogen replacement therapy have shown the ability to reduce risk of colon cancer development in clinical and animal studies, but in vitro research has been unable to reproduce an estradiol (E2) induced response in colon cancer cell lines. We demonstrated that young adult mouse colonocytes (YAMC, non-malignant colonocytes) exhibit an anti-proliferative response to E2 treatment. These cells demonstrate reduced cell culture growth and increased apoptosis in response to E2. YAMC cells containing an activated Ras mutation are considered to be malignantly transformed, and lose the ability to respond to E2 treatment. Fulvestrant (ICI) was used as an estrogen receptor antagonist to determine that these results were estrogen receptor mediated. Furthermore, this effect was demonstrated to require the presence of ER? through the use of a transgenic ERbeta knockout mouse. In these mice, the presence of E2 significantly reduced the formation of azoxymethane induced premalignant lesions. Since YAMC cells exhibit an anti-proliferative response to E2 treatment, we utilized isogenic YAMC cell lines with and without a dominant negative p53 mutation to demonstrate that this E2 induced action involves p53 activity. E2 treatment results in increased p53 transcriptional activity and a pro-apoptotic change in expression of p53 downstream targets. Presence of the dominant negative p53 mutant nullifies these effects of E2 treatment. The involvement of p53 in the previously described protection against AOM induced premalignant lesions, was investigated using wild type and heterozygous p53 knockout (Het p53KO) mice. The reduction in p53 protein corresponded to reduced effectiveness of E2 treatment on the prevention of premalignant lesion formation in Het p53KO mice. In summary, our data indicate that E2 treatment induces anti-proliferative responses in non-malignant colonocytes and protects against the formation of carcinogen-induced premalignant lesions. These effects require the presence of functional ER? and p53. Further studies are required to more thoroughly elucidate the specific interactions and downstream effects of ER? and p53 in response to E2 stimulation.

Several members of the lysyl oxidase family of copper-dependent amine oxidases have been implicated in tumor development. The Iysyl oxidase (LOX) and LOX-like 2 (LOXL2) genes have been mapped to chromosomal regions affected by loss of heterozygosity (LOH) in several cancers, including those of the colon and esophagus. Indeed, there have been numerous reports of reduced LOX and a few reports of reduced LOXL2 expression in various cancers. Identification of microsatellite markers within the LOX locus and the LOXL2 gene allowed for evaluation ofthe status of these gene alleles in colon and esophageal tumors. There was significant LOH of the LOX locus in colon tumors that was accompanied by reduced mRNA expression and a spectrum of alterations and mutations affecting the LOX gene. This study demonstrated, for the first time, that genetic events, namely LOH, deletions and mutations ofthe LOX gene, were responsible, at least partly, for the reduction of LOX gene expression. There was also significant LOH of the LOXL2 gene in both colon and esophageal tumors. However, instead of a reduction of LOXL2 expression, there was increased expression that correlated with less differentiated tumors and absent elastosis, both indicators of poor prognosis. Further studies indicated that both LOX and LOXL2 are absent in non-invasive tumor cell lines but re-expressed in invasive cell lines, likely as part of the thelial-mesenchymal transition that occurs in the last steps of tumorigenesis to facilitate metastasis. The results presented and research strategy outlined in this dissertation will define the importance of LOXL2 amine oxidase activity and protein interactions in the critical but poorly understood process oftumor cell migration and invasion.