Advanced Stages Of Colon Cancer Research Articles

Genetic insights and therapeutic potential for colorectal cancer: mutation analysis of KRASgene and efficacy of Oleuropein-conjugated iron oxide nanoparticles.

This study aimed to address the challenges of treating advanced stages of colon cancer (CRC) by exploring potential therapeutic options. The research focused on the genetic aspects of CRC, specifically the mutation rate of the KRAS gene, along with other genes like TTN, APC, MUC16, and TP53, using the TCGA dataset. Additionally, the study investigated the efficacy of Oleuropein, a polyphenolic compound found in olives, in combating CRC by using iron oxide nanoparticles coated with glucose and conjugated with Oleuropein. The study characterized the physicochemical properties of the nanoparticles, and the cytotoxic effects of the nanoparticles were evaluated on CRC and normal fibroblast cell lines, demonstrating significantly higher cytotoxicity against CRC cells compared to normal cells. Furthermore, the study analyzed gene expression changes using the GSE124627 dataset to understand the influence of KRAS alterations. It identified numerous upregulated and downregulated genes in KRAS-overexpressing samples, suggesting their involvement in critical cancer-related pathways. These findings suggest that KRAS-influenced genes could serve as potential therapeutic targets for CRC treatment. The study also examined the expression levels of identified genes in CRC samples compared to normal samples. Among the upregulated genes, 22 showed significant increases in cancer samples, while 14 downregulated genes exhibited decreased expression in both KRAS-influenced and cancer samples. Cox regression analysis identified specific upregulated genes, including ANKZF1, SNAI1, PPFIA4, SIX4, and NOTUM, associated with poor prognosis. Kaplan-Meier analysis further confirmed the correlation between increased expression of these genes and higher patient mortality rates. In conclusion, this study provided valuable insights into the genetic aspects of CRC and potential therapeutic strategies. The use of Oleuropein-conjugated iron oxide nanoparticles showed promising cytotoxic effects on colon cancer cells. These findings contribute to advancing our understanding of CRC and offer potential targets for further investigation and the development of novel therapeutic approaches.

Assessing Changes in Colon Cancer Care during the COVID-19 Pandemic: A Four-Year Analysis at a Romanian University Hospital.

This retrospective study investigates the impact of the COVID-19 pandemic on the surgical management of patients with colon cancer in a tertiary University Hospital in Timisoara, Romania. Data from 867 patients who underwent surgical interventions for this condition between 26 February 2019 and 25 February 2023 were meticulously analyzed to evaluate substantial shifts in the management and outcomes of these patients in comparison to the pre-pandemic era. The results reveal a substantial decrease in elective surgical procedures (p < 0.001) and a significant increase in emergency interventions (p < 0.001). However, postoperative mortality did not show significant variations. Of concern is the diagnosis of patients at more advanced stages of colon cancer, with a significant increase in Stage IV cases in the second year of the pandemic (p = 0.045). Average hospitalization durations recorded a significant decrease (p < 0.001) during the pandemic, and an inverse correlation between patient age and surgery duration was reported (p = 0.01, r = -0.088). This analysis provides a comprehensive perspective on how the pandemic has influenced the management of colon cancer, highlighting significant implications for the management and outcomes of these patients.

Synergistic Effect of L-cycloserine and Capecitabine on Human Colon Cancer Cell Line

Introduction: Colon cancer comes in second place in the list of cancers in developed countries. Drug resistance is one of the causes of colorectal cancer therapeutic failure that usually occurs in most patients in advanced stage of colon cancer. This study investigates the effect of adding L-cycloserine to capecitabine in the HCT-116 colon cancer cell line. Materials and methods: We compared the combined L-cycloserine-capecitabine effect with each of the two drugs alone on the HCT-116 colon cancer cell line as a positive control group. The growth rate inhibition was examined by crystal violet assay. Results: The growth inhibition effect of L-cycloserine-capecitabine, L-cycloserine and capecitabine on HCT-116 cells was assessed with crystal violet assay, different concentrations including 3.12, 6.25, 12.5, 25, 50, and 100 μg/mL were used for L-cycloserine-capecitabine combination, and for both L-cycloserine and capecitabine. After incubation for 24 hours, results appeared that the combination of L-cycloserine and capecitabine increased the effect of both drugs alone as seen by a significant increase (p &lt;0.05) of the growth inhibition percentages in the L-cycloserine-capecitabine combination as compared with the positive control groups. Conclusion: From the result, we can conclude that the L-cycloserine combination with capecitabine has a synergistic effect for colon cancer treatment that could be a more effective regimen.

The effect of resveratrol and quercetin intervention on azoxymethane-induced colon cancer in Rats model

<h2>Summary</h2><h3>Background</h3> Among gastrointestinal cancers, colon cancer is the fourth leading cause of death in the world, accounting for about 8% of all cancer deaths. Early detection of colon cancer can play an important role in survival in recent years. Although chemotherapy drugs prevent cells from proliferating in certain tissues of the body and induce apoptosis in tumor cells, one of the problems is that treatments for advanced stages of colon cancer have detrimental effects on the patient the American Society of Clinical Oncology (ASCO) proposed natural or synthetic substances that can prevent the recurrence of cancer or slow down the progression of cancer as preventative substances with chemical mechanisms. Resveratrol and quercetin are the natural compounds that has biological effects in the prevention and treatment of cancer. Therefore, the purpose of current study was evaluated the effect of quercetin and resveratrol in colon cancer rats. <h3>Materials and methods</h3> Fifty-five male Sprague dawley rats were randomly assigned to healthy group, control group, resveratrol group, quercetin group and combination of resveratrol and quercetin treated group. At the fourth week animals received azoxymethane (AOM) (15 mg/kg) subcutaneous as a carcinogenic agent weekly for two consecutive weeks except for healthy group. The resveratrol (8 mg/kg) and quercetin (10 mg/kg) intervention done from two weeks before carcinogenesis induction until week 19 via oral gavage. The effect of resveratrol and quercetin was investigated on apoptosis by M30 antibody, cell proliferation by AgNOR staining, histopathological and histomorphological examination of AOM-induced colon cancer in rats model. Other findings were measured by using a beta-catenin count under a microscope. <h3>Result</h3> The highest frequency and highest percentage of nuclear polymorphism scores are observed in the control group, resveratrol, quercetin, and resveratrol + quercetin, respectively. In mucosal stratification the highest frequency and severity of low anomalies are related to resveratrol+ quercetin group and the highest frequency and severity of anomalies are related to control group. Also, in loss of nuclear polarity the highest frequency and low severity of anomalies are related to quercetin group and the highest frequency and severity is related to the control group. In goblet cells the highest frequency and lowest severity of anomalies are related to resveratrol + quercetin group and the highest frequency and severity of anomalies are related to control group. The highest frequency and lowest rate of crypt anomalies is related to resveratrol + quercetin group and the highest frequency and rate of crypt anomaly is related to control group. The highest and lowest mean of M30 expression are in healthy and control group, respectively. The highest and lowest mean of AgNOR are related to control and healthy groups, respectively. Beta-catenin proteins expression was lower in the combination of resveratrol and quercetin group in versus to others group. <h3>Conclusion</h3> Intervention of resveratrol and quercetin supplements together can be promising as a therapeutic strategy in future studies for colon cancer.

A novel LncRNA HITT forms a regulatory loop with HIF-1α to modulate angiogenesis and tumor growth.

Increasing evidence has indicated that long noncoding RNAs (lncRNAs) play important roles in human diseases, including cancer; however, only a few of them have been experimentally validated and functionally annotated. Here, we identify a novel lncRNA that we term HITT (HIF-1α inhibitor at translation level). HITT is commonly decreased in multiple human cancers. Decreased HITT is associated with advanced stages of colon cancer. Restoration of the expression of HITT in cancer cells inhibits angiogenesis and tumor growth in vivo in an HIF-1α-dependent manner. Further study reveals that HITT inhibits HIF-1α expression, mainly by interfering with its translation. Mechanically, HITT titrates away YB-1 from the 5'-UTR of HIF-1α mRNA via a high-stringency YB-1-binding motif. The reverse correlation between HITT and HIF-1α expression is further validated in human colon cancer tissues. Moreover, HITT is one of the most altered lncRNAs upon the hypoxic switch and HITT downregulation is required for hypoxia-induced HIF-1α expression. We further demonstrate that HITT and HIF-1α form an autoregulatory feedback loop where HIF-1α destabilizes HITT by inducing MiR-205, which directly targets HITT for degradation. Together, these results expand our understanding of the cancer-associated functions of lncRNAs, highlighting the HITT-HIF-1α axis as constituting an additional layer of regulation of angiogenesis and tumor growth, with potential implications for therapeutic targeting.

ACLY facilitates colon cancer cell metastasis by CTNNB1

BackgroundColon cancer is the second leading cancer worldwide. Recurrent disease and chemotherapeutic drug resistance are very common in the advanced stage of colon cancer. ATP-citrate lyase (ACLY), the first-step rate-controlling enzyme in lipid synthesis, is elevated in colon cancer. However, it remains unclear about the exact role of ACLY in the development of colon cancer metastasis.MethodsTo evaluate the role of ACLY in colon cancer metastasis, we performed cell migration and invasion assays in two ACLY-deficient colon cancer cell lines. Colon cancer mouse model is used to examine ACLY’s effects on colon metastasis potentials in vivo. We analyzed the correlation between ACLY and CTNNB1 protein in 78 colon cancer patients by Pearson correlation. To finally explore the relationship of ACLY and CTNNB1, we used western blots, migration and invasion assays to confirm that ACLY may regulate metastasis by CTNNB1.ResultsOur data showed that the abilities of cell migration and invasion were attenuated in ACLY-deficient HCT116 and RKO cell lines. Furthermore, we describe the mechanism of ACLY in promoting colon cancer metastasis in vitro and in vivo. ACLY could stabilize CTNNB1 (beta-catenin 1) protein by interacting, and the complex might promote CTNNB1 translocation through cytoplasm to nucleus, subsequently promote the CTNNB1 transcriptional activity and migration and invasion abilities of colon cancer cells. Immunohistochemical analysis of 78 colon cancer patients showed that the high expression levels of ACLY and CTNNB1 protein was positively correlated with metastasis of colon cancer.ConclusionsThese results shed new light on the molecular mechanism underlying colon cancer metastasis, which might help in improving therapeutic efficacy.

Invasive Colon Cancer Cells Induce Transdifferentiation of Endothelium to Cancer-Associated Fibroblasts through Microtubules Enriched in Tubulin-β3.

Colon cancer, the second leading cause of cancer-related deaths in the world, is usually diagnosed in invasive stages. The interactions between cancer cells and cells located in their niche remain the crucial mechanism inducing tumor metastasis. The most important among those cells are cancer-associated fibroblasts (CAFs), the heterogeneous group of myofibroblasts transdifferentiated from numerous cells of different origin, including endothelium. The endothelial-to-mesenchymal transition (EndMT) is associated with modulation of cellular morphology, polarization and migration ability as a result of microtubule cytoskeleton reorganization. Here we reveal, for the first time, that invasive colon cancer cells regulate EndMT of endothelium via tubulin-β3 upregulation and its phosphorylation. Thus, we concluded that therapies based on inhibition of tubulin-β3 expression or phosphorylation, or blocking tubulin-β3’s recruitment to the microtubules, together with anti-inflammatory chemotherapeutics, are promising means to treat advanced stages of colon cancer.

The silent healer: miR-205-5p up-regulation inhibits epithelial to mesenchymal transition in colon cancer cells by indirectly up-regulating E-cadherin expression

EMT represents the dominant program within advanced stages of colon cancer, where cells acquire migratory characteristics in order to invade secondary tissues and form metastasis. Where the majority of the therapeutic strategies are concentrated on the reduction of the tumor mass through different apoptotic mechanisms, the present study advocates an important role for miR-205-5p in impairment of colon cancer cells migration and restoration of the epithelial phenotype. Upon identification of a homogenous downregulated profile for miR-205-5p in colon adenocarcinoma patients, functional studies demonstrated that experimental upregulation of this sequence is able to significantly raise the levels of E-cadherin through direct inhibition of ZEB1. Moreover, the elevation in CDH1 expression was translated into functional parameters where cells lost their invasion and migratory characteristics and formed homogenous clusters through adhesion interactions. Survival analysis of colon adenocarcinoma patients revealed that low levels of miR-205-5p are associated with an unfavorable prognostic compared to those with increased expression, demonstrating the possible clinical utility of miR-205-5p replacement. Exogenous administration of miRNA mimics was not associated with significant changes in cell viability or inflammatory pathways. Therefore, the proposed strategy is aiming towards inhibition of metastasis and limitation of the tumor borders in advanced stages patients in order to prolong the survival time and to increase the efficiency of the current therapeutic strategies.

High RAC3 expression levels are required for induction and maintaining of cancer cell stemness.

RAC3 is a transcription coactivator, usually overexpressed in several tumors and required to maintain the pluripotency in normal stem cells.In this work we studied the association between RAC3 overexpression on cancer cell stemness and the capacity of this protein to induce cancer stem properties in non tumoral cells.We performed in vitro and in vivo experiments using two strategies: by overexpressing RAC3 in the non tumoral cell line HEK293 and by silencing RAC3 in the human colorectal epithelial cell line HCT116 by transfection. Furthermore, we analysed public repository microarrays data from human colorectal tumors in different developmental stages. We found that RAC3 overexpression was mainly associated to CD133+ side-population of colon cancer cells and also to early and advanced stages of colon cancer, involving increased expression of mesenchymal and stem markers. In turn, RAC3 silencing induced diminished tumoral properties and cancer stem cells as determined by Hoechst efflux, tumorspheres and clonogenic growth, which correlated with decreased Nanog and OCT4 expression. In non tumoral cells, RAC3 overexpression induced tumoral transformation; mesenchymal phenotype and stem markers expression. Moreover, these transformed cells generated tumors in vivo.Our results demonstrate that RAC3 is required for maintaining and induction of cancer cell stemness.

H19 Overexpression Induces Resistance to 1,25(OH)2D3 by Targeting VDR Through miR-675-5p in Colon Cancer Cells

The long noncoding (lnc) RNA H19 was involved in the tumorigenesis of many types of cancer. However, the role of H19 in the tumorigenesis of colon cancer has not been fully illustrated. Recent studies suggested a potential relationship between H19 and vitamin D receptor (VDR) signaling. Considering the pivotal role of VDR signaling in the colon epithelium both physiologically and pathologically, the correlation between H19 and VDR signaling may have an important role in the development of colon cancer. In this study, the correlation between H19 and vitamin D receptor (VDR) signaling and the underlying mechanisms in colon cancer were investigated both in vitro and in vivo. The results suggested that VDR signaling was able to inhibit the expression of H19 through regulating C-Myc/Mad-1 network. H19, on the other hand, was able to inhibit the expression of VDR through micro RNA 675-5p (miR-675-5p). Furthermore, H19 overexpression induced resistance to the treatment with 1,25(OH)2D3 both in vitro and in vivo. Together, these results suggested that H19 overexpression might be one of the mechanisms underlying the development of resistance to the treatment with 1,25(OH)2D3 in the advanced stage of colon cancer.

Abstract 2500: Grape compounds suppress colon cancer stem cells in vitro and in a rodent model of colon carcinogenesis

Abstract We have previously shown that the grape bioactive compound resveratrol (RSV) potentiates grape seed extract (GSE)-induced colon cancer cell apoptosis at physiologically relevant concentrations. However, RSV-GSE combination efficacy against colon cancer stem cells (CSCs), which play a key role in chemotherapy and radiation resistance, is not known. Hence, we tested the anti-cancer efficacy of the RSV-GSE in an azoxymethane-induced mouse model of colon carcinogenesis. RSV-GSE suppressed tumor incidence similar to sulindac, without any gastrointestinal toxicity. Additionally, RSV-GSE treatment reduced the number of crypts containing cells with nuclear β-catenin (an indicator of colon CSCs) via induction of apoptosis. In in vitro mechanistic studies, RSV-GSE suppressed proliferation and sphere formation properties of colon CSCs (positive for CD44, CD133 and ALDH1b1), suppressed pGSK3β and nuclear translocation of β-catenin, a critical regulator of CSC proliferation, similar to sulindac. RSV-GSE, but not sulindac, suppressed nuclear levels of downstream proteins of Wnt/β-catenin pathway, c-Myc and cyclin D1. RSV-GSE also induced mitochondrial-mediated apoptosis in colon CSCs characterized by elevated p53, Bax/Bcl-2 ratio and cleaved PARP. Furthermore, shRNA-mediated knockdown of p53, a tumor suppressor gene that is mutated in advanced stages of colon cancer, in the colon CSCs did not alter efficacy of RSV-GSE. The suppression of Wnt/β-catenin signaling and elevated mitochondrial-mediated apoptosis in colon CSCs support potential clinical testing/application of grape bioactives for colon cancer prevention and/or therapy. Citation Format: Lavanya Reddivari, Venkata Charepalli, Ramakrishna Vadde, Sridhar Radhakrishnan, Joshua D. Lambert, Ryan J. Elias, Jairam KP Vanamala. Grape compounds suppress colon cancer stem cells in vitro and in a rodent model of colon carcinogenesis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2500.

Antioxidant supplementation accelerates cachexia development by promoting tumor growth in C26 tumor-bearing mice

More than 50% of patients with advanced stages of colon cancer suffer from progressive loss of skeletal muscle, called cachexia, resulting in reduced quality of life and shortened survival. It is becoming evident that reactive oxygen species (ROS) regulate pathways controlling skeletal muscle atrophy. Herein we tested the hypothesis that antioxidant supplementation could prevent skeletal muscle atrophy in a model of cachectic Colon 26 (C26) tumor-bearing mice. Seven-week-old BALB/c mice were subcutaneously inoculated with colon 26 (C26) cancer cells or PBS. Then C26-mice were daily gavaged during 22 days either with PBS (vehicle) or an antioxidant cocktail whose composition is close to that of commercial dietary antioxidant supplements (rich in catechins, quercetin and vitamin C). We found that antioxidants enhanced weight loss and caused premature death of mice. Antioxidants supplementation failed to prevent (i) the increase in plasma TNF-α levels and systemic oxidative damage, (ii) skeletal muscle atrophy and (iii) activation of the ubiquitin-proteasome system (MuRF-1, MAFbx and polyubiquitinated proteins). Accordingly, immunohistological staining for Ki-67 and the expression of cell cycle inhibitors demonstrated that tumor of supplemented mice developed faster with a concomitant decrease in oxidative damage. Previous studies have shown that the use of catechins and quercetin separately can improve the musculoskeletal function in cachectic animals. However, our results indicate that the combination of these antioxidants reduced survival and enhanced cachexia in C26-mice.

OP17 - Natural antioxidants accelerate cachexia development in colon cancer

Cancer cachexia is a multifactorial syndrome and a complex metabolic disorder, characterized by a continuous loss of muscle mass with or without depletion of adipose tissue. It manifests mainly in patients with advanced stages of colon cancer and accounts for more than 20% of mortality in total cancer patients. Muscle atrophy is one of the most relevant clinical events in cancer cachexia that negatively impact patient’s quality of life. Currently, it is well established and recognized that cachexia-induced muscle atrophy is intimately linked to oxidative stress (OS), since oxidative damages were increased in the skeletal muscle of cachectic patients and were positively correlated with muscle proteolysis. Thus, supplementation with natural antioxidants could be a valuable strategy to prevent the deterioration of patient’s quality of life and/or alleviate cachexia-related symptoms, like muscle atrophy. Herein, we tested the effectiveness of this strategy in a model of C26-tumor bearing mice. Five-week old Balb/c mice have received a subcutaneous injection of PBS or C26 cancer cells with or without daily supplementation with a cocktail of natural antioxidants. Venous blood and skeletal muscles were removed at 20-22 days after injection. We found that supplemented mice started to lose weight faster and died prematurely compared to no supplemented mice. Muscle atrophy occurred earlier in supplemented mice as evidenced by the decrease in fibers diameter, skeletal muscle weights and muscle endurance. These events were concomitant with an increase in systemic and muscular oxidative stress (e.g. carbonyls proteins, 4-HNE). Surprisingly, oxidative damage markers were decreased only in tumor of antioxidants-supplemented mice and were associated with a decrease in cell cycle inhibitors expression (e.g. p21), leading to tumor proliferation and progression. In line with recently published reports, our study support the evidence that antioxidants supplementation, if there is no need, could have deleterious consequences on health and well-being.

Abstract 49: Zinc finger protein 185 is a key molecule of liver metastasis in colon cancer

Abstract Colorectal cancer is among the three leading causes of cancer-related deaths worldwide. Nearly 50% of patients with colon cancer develop liver metastases. Mortality associated with the advanced stage of colon cancer has principally been attributed to the development of liver metastases. Therefore, clarifying the biological mechanisms underlying liver metastasis from colon cancer and accelerating the development of new treatment strategies are needed. We isolated Zinc finger protein 185 (ZNF185) as a metastasis-related protein by global quantitative proteome analysis of the in vivo liver metastasis model of super immunodeficient NOG mice with the highly liver-metastatic subline SW48-LM2 (Matsuo E, et al. AACR, #3947, 2008). LIM domain proteins have many fundamental biological processes including cell lineage specification, cytoskeleton organization, and organ development. ZNF185 is one of the LIM domain proteins and is considered to be involved in regulating cellular differentiation and/or proliferation. However, the functions and properties of ZNF185 in the multi-step process of cancer biology have not yet been elucidated in detail. In the present study, we analyzed the relationships between ZNF185 and the clinicopathological features of colon cancer (age, gender, histological type, lymphatic involvement, venous involvement, T and N statuses, liver metastasis, and stage). The expression of the ZNF185 protein was immunohistochemically analyzed. The expression of ZNF185 was detected in the cancer cells of 78 of 87 colon cancer patients. A correlation was observed between ZNF185 and the histological type (p=0.010, G-test). The expression of ZNF185 was also correlated with liver metastasis (p=0.030, G-test). Multivariate analysis using the Cox proportional hazards model was performed among the cause-specific survival rate, ZNF185 expression, and clinicopathological features. The histological type, liver metastasis, and ZNF185 expression were found to be independent prognostic indicators (p= 0.028, p&amp;lt;0.0001, p=0.036, respectively). ZNF185 expression was found to be an independent indicator of liver metastasis and prognosis in colon cancer. Citation Format: Daisuke Furukawa, Tsuyoshi Chijiwa, Masahiro Matsuyama, Masaya Mukai, Ei-ichi Matsuo, Osamu Nishimura, Kenji Kawai, Hiroshi Suemizu, Nobuyoshi Hiraoka, Toshio Nakagohri, Seiei Yasuda, Masato Nakamura. Zinc finger protein 185 is a key molecule of liver metastasis in colon cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 49. doi:10.1158/1538-7445.AM2014-49

Protein kinase D1 attenuates tumorigenesis in colon cancer by modulating β-catenin/T cell factor activity.

Over 80% of colon cancer development and progression is a result of the dysregulation of β-catenin signaling pathway. Herein, for the first time, we demonstrate that a serine-threonine kinase, Protein Kinase D1 (PKD1), modulates the functions of β-catenin to suppress colon cancer growth. Analysis of normal and colon cancer tissues reveals downregulation of PKD1 expression in advanced stages of colon cancer and its co-localization with β-catenin in the colon crypts. This PKD1 downregulation corresponds with the aberrant expression and nuclear localization of β-catenin. In-vitro investigation of the PKD1-β-catenin interaction in colon cancer cells reveal that PKD1 overexpression suppresses cell proliferation and clonogenic potential and enhances cell-cell aggregation. We demonstrate that PKD1 directly interacts with β-catenin and attenuates β-catenin transcriptional activity by decreasing nuclear β-catenin levels. Additionally, we show that inhibition of nuclear β-catenin transcriptional activity is predominantly influenced by nucleus targeted PKD1. This subcellular modulation of β-catenin results in enhanced membrane localization of β-catenin and thereby increases cell-cell adhesion. Studies in a xenograft mouse model indicate that PKD1 overexpression delayed tumor appearance, enhanced necrosis and lowered tumor hypoxia. Overall, our results demonstrate a putative tumor-suppressor function of PKD1 in colon tumorigenesis via modulation of β-catenin functions in cells.

Overexpression of microRNA-122 re-sensitizes 5-FU-resistant colon cancer cells to 5-FU through the inhibition of PKM2 in vitro and in vivo.

5-Fluorouracil (5-FU) is one of the most commonly used anticancer drugs in the treatment of colon cancer. However, acquired chemoresistance is becoming one of the major challenges for patients with advanced stages of colon cancer. Currently, the mechanisms underlying cancer cell resistance to 5-FU are not fully understood. MicroRNAs (miRNA) have been suggested to play important roles in tumorigenesis and drug resistance in colon cancer. In this study, we generated 5-FU-resistant colon cancer cell lines from which we found that miR-122 was downregulated in 5-FU-resistant cells compared with sensitive cells. Meanwhile, the glucose metabolism is significantly upregulated in 5-FU-resistant cells. We report that PKM2 is a direct target of miR-122 in colon cancer cell. Importantly, overexpression of miR-122 in 5-FU-resistant cells resensitizes 5-FU resistance through the inhibition of PKM2 both in vitro and in vivo. In summary, these findings reveal that the dysregulated glucose metabolism contributes to 5-FU resistance, and glycolysis inhibition by miR-122 might be a promising therapeutic strategy to overcome 5-FU resistance.

The Protective Effect of Cell Wall and Cytoplasmic Fraction of Selenium Enriched Yeast on 1, 2-Dimethylhydrazine-induced Damage in Liver

Background and Aim: 1, 2-Dimethylhydrazine (DMH) enhances lipid peroxidation rate by tumor mitochondria than normal tissue counterpart and causes many disorders in antioxidant system in live r. It also increases the level of enzymes that metabolize toxin in liver and colon. T he aim of this study was to evaluate the alteration of liver and its enzymes af ter DMH injection and evaluate protective effect of cell wall and cytoplasmic frac tions of Saccharomyces cereviseae enriched with selenium (Se) on these tissues. Methods: Forty eight female rats were prepared and acclimat ized to the laboratory conditions for two weeks, and all animals received 1, 2- dimethyl hydrazine chloride (40 mg/kg body weight) twice a week for 4 weeks except healthy control. At first colon carcinoma (aberrant crypt foci) conf irmed by light microscope. Then the changes resulting from injection of DMH on live r of animals in initial and advanced stages of colon cancer were examined. In addition, the protective effect of cell wall and cytoplasmic fractions of Selenium- enriched S. cerevisiae were investigated in two phases. First phase in initial stage and second phase in advanced stage of colon cancer were performed respectively. Forty weeks following the first DMH injection, all survived ani mals were sacrificed. Then, colon and liver removed and exsanguinated by heart puncture. For measuring the levels of enzymes (AST, ALT, and ALP), a commercial kit (Parsazmoon, Iran) and an autoanalyzer (BT 3000 Pluse, Italy) were use d. Results: The results showed that subcutaneous injection of DMH increased the ALT, AST, and ALP levels up to 78.5, 161.38, and 275.88 U/L compared to the control, respectively. Moreover, statistical analys is in both phases of experiment revealed that the enzyme levels were decreased in t he treated groups in comparison with the DMH-injected group, while the levels of these enzymes were lower in the control group. Conclusion: It should be concluded that administration of cell wall and cytoplasmic fraction prepared from Se-enriched S. cerevisiae could reduce the tissue damages in the livers DMH-injected rats. Thi s beneficial effect would warrant further study on the clinical application o f Se-enriched yeast.

Immunohistochemical study of estrogen receptor β expression in colonic adenocarcinoma

Background Colonic adenocarcinoma is the most frequent neoplasia of the intestine. This pathology is the third highest cause of death from cancer. The large majority of colorectal malignancies develop from an adenomatous polyp (adenoma). Estrogen receptor (ER)-β-induced inhibition of proliferation could be explained by the inhibition of the bcl-2 gene. ER-β protein levels are reportedly lower in colon tumors compared with normal colon tissue, and loss of ER-β is associated with advanced stages of colon cancer and tumor cell dedifferentiation, suggesting a protective role for ER-β in colon tumorigenesis. Aim The aim of the work was to assess the expression of ER-β in cases of colonic adenocarcinoma and adenomatous polyps, and its relation to tumorigenesis. Materials and methods Sixty archival formalin-fixed paraffin-embedded, routinely processed cases, constituting 40 cases of colonic adenocarcinoma and 20 cases of adenomatous polyps, were included in this study. For each selected case, clinical data were retrieved from the computer files. Results In this study, loss of ER-β expression was present in a larger number of adenocarcinoma cases (n=25) than in adenomatous polyps (n=5). ER-β expression showed a nonsignificant correlation between age and sex distribution in the studied cases of colonic adenocarcinoma and adenomatous polyps. ER-β expression showed significant correlation between the site and the size distribution in the studied cases of colonic adenocarcinoma and adenomatous polyps. ER-β expression is inversely proportional to the colonic adenocarcinoma stage and grade as the highest frequency of positive ER-β expression in the studied cases of colonic adenocarcinoma occurred in well-differentiated tumors (25%) and in modified Dukes’ stage B1 (20%) (P Conclusion and recommendations ER-β may protect normal colonic epithelial cells from undergoing unscheduled cell proliferation and neoplastic transformation. ER-β expression is related to tumorigenesis and prognostic factors in colonic adenocarcinoma. ER-β expression decreases in adenomas and colonic adenocarcinoma. Further studies are recommended to prove the protective effect of estrogen hormone replacement therapy against colonic adenocarcinoma in high-risk patients.

Quantitative secretome analysis reveals the interactions between epithelia and tumor cells by in vitro modulating colon cancer microenvironment

In tumor microenvironment, interactions among multiple cell types are critical for cancer progression. Secreted proteins are responsible for crosstalk among these cells within tumor microenvironment. To elucidate the interactions of tumor and epithelia, we co-cultured colon cancer cell line HT29 with normal human colon mucosal epithelial cell line NCM460 to mimic tumor microenvironment in vitro and investigated the differential expression pattern of secretome. A quantitative proteomics approach based on stable isotope labeling by amino acids in cell culture (SILAC) and LC-mass spectrometry was used for secretome analysis. Totally 45 proteins were altered over 2-fold in co-cultured cellular supernatants between equal amounts of NCM460 and HT29 cells, compared with mono-cultured conditions. These differential secreted proteins involve in multiple tumor-associated biological functions. The secretion level and acting pattern of acrogranin, IGFBP6 and vimentin were changed along with different co-cultured cell number ratios between NCM460 and HT29 cells, simulating early, middle or advanced stage of colon cancer. Therefore, a quantitative secretome profiling based on a co-culture system can track secreted protein changes and their associated biological roles between tumor and epithelia, which gives a new insight on communications between tumor and epithelia as well as cancer biotherapy by inhibiting cell interactions. Tumor microenvironment is a complex system and comprised of cancer cells and host stromal cells. The growth and progression of tumor have been recognized were affected by multidirectional interactions of secreted proteins (secretome), which were produced by the cells within tumor microenvironment. Focus on general secreted molecules of living cells via proteomic tools, is promising for investigating cell communication. Stable isotope labeling by amino acids in cell culture (SILAC) is a metabolic labeling strategy for quantitative analysis, which is gaining popularity because of its ease of implementation, the high quality of quantitative data obtained, robustness and compatibility with existing experimental workflows. Therefore, SILAC-based quantitative secretome analysis was employed for investigating interactions between epithelia and tumor by in vitro modulating colon cancer microenvironment with established co-culture system, which simplified the complexity of cancer microenvironment, also tracked secreted protein changes and their associated biological roles between epithelia and cancer cells. A series of tumor associated secreted proteins was quantitated and investigated in our study. So, the results give a new insight on communications between tumor and epithelia as well as cancer biotherapy by inhibiting interactions of them.

Abstract 3200: Spliced variant of T-cell intercellular antigen 1 (TIA-1) in colorectal cancer.

Abstract Alternative splicing regulates many cancer-associated genes. Splice isoforms that are found in tumors could have diagnostic value and may provide potential drug targets. We identified an endogenous splice variant of TIA-1 (T-cell intercellular antigen-1), short TIA-1 (shTIA-1), expressed in invasive colon cancer cells, which was not expressed in non-invasive adenoma cell lines. In this study we investigated the frequency of shTIA-1 expression in human normal and cancer tissue and if it correlates with advanced-stage of colon cancer. RNA was extracted from 25μm thick scrolls of formalin fixed paraffin embedded sections of 40 colorectal carcinoma (20 Duke's, 20 Duke's C stage) and normal samples. RT-PCR was carried out to detect full length (flTIA-1) and shTIA-1. Immunohistochemical CD31 staining of microvessels in the same samples was used to assess microvessel density (MVD) and correlate the shTIA isoform expression and stages of the tumors. The results showed that flTIA-1 was less frequently found in tumour than in normal tissues (p=0.002). shTIA-1 was more highly expressed than flTIA-1 and in significantly higher portion of tumors than normal samples (p=0.0106). There was a significantly lower proportion of Duke's B than Duke's C grade tumours with detectable shTIA-1 expression (p=0.018). CD31 staining showed samples with shTIA-1 associated with increased MVD. We did not find any association between stages and MVD, as there was no statistically significant difference in MVD between Duke's B and Duke's C. However tumours had higher MVD than normal tissues from the same patients. These results indicate that a splice variant of TIA-1 is expressed in human colorectal carcinoma and is associated with increased angiogenesis. Citation Format: Maryam Hamdollah-Zadeh, Xi Ye, Enric Domingo, David J. Kerr, Mike R. Ladomery, Steve J. Harpar, Dave O. Bates. Spliced variant of T-cell intercellular antigen 1 (TIA-1) in colorectal cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3200. doi:10.1158/1538-7445.AM2013-3200