Strategy For Treatment Of Colorectal Cancer Research Articles

Flavopereirine Suppresses the Growth of Colorectal Cancer Cells through P53 Signaling Dependence.

Colorectal cancer (CRC) is a significant cause of morbidity and mortality worldwide. The outcome of CRC patients remains poor. Thus, a new strategy for CRC treatment is urgently needed. Flavopereirine is a β-carboline alkaloid extracted from Geissospermum vellosii, which can reduce the viability of various cancer cells through an unknown mode of action. The aim of the present study was to investigate the functional mechanism and therapeutic potential of flavopereirine on CRC cells in vitro and in vivo. Our data showed that flavopereirine significantly lowered cellular viability, caused intrinsic and extrinsic apoptosis, and induced G2/M-phase cell cycle arrest in CRC cells. Flavopereirine downregulated Janus kinases-signal transducers and activators of transcription (JAKs-STATs) and cellular myelocytomatosis (c-Myc) signaling in CRC cells. In contrast, the enforced expressions of constitutive active STAT3 and c-Myc could not restore flavopereirine-induced viability reduction. Moreover, flavopereirine enhanced P53 expression and phosphorylation in CRC cells. CRC cells with P53 knockout or loss-of-function mutation significantly diminished flavopereirine-mediated viability reduction, indicating that P53 activity plays a major role in flavopereirine-mediated CRC cell growth suppression. Flavopereirine also significantly repressed CRC cell xenograft growth in vivo by upregulating P53 and P21 and inducing apoptosis. In conclusion, flavopereirine-mediated growth suppression in CRC cells depended on the P53-P21, but not the JAKs-STATs-c-Myc signaling pathway. The present study suggests that flavopereirine may be efficacious in the clinical treatment of CRC harboring functional P53 signaling.

Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines 2019 for the treatment of colorectal cancer

The number of deaths from colorectal cancer in Japan continues to increase. Colorectal cancer deaths exceeded 50,000 in 2016. In the 2019 edition, revision of all aspects of treatments was performed, with corrections and additions made based on knowledge acquired since the 2016 version (drug therapy) and the 2014 version (other treatments). The Japanese Society for Cancer of the Colon and Rectum guidelines 2019 for the treatment of colorectal cancer (JSCCR guidelines 2019) have been prepared to show standard treatment strategies for colorectal cancer, to eliminate disparities among institutions in terms of treatment, to eliminate unnecessary treatment and insufficient treatment and to deepen mutual understanding between healthcare professionals and patients by making these guidelines available to the general public. These guidelines have been prepared by consensuses reached by the JSCCR Guideline Committee, based on a careful review of the evidence retrieved by literature searches and in view of the medical health insurance system and actual clinical practice settings in Japan. Therefore, these guidelines can be used as a tool for treating colorectal cancer in actual clinical practice settings. More specifically, they can be used as a guide to obtaining informed consent from patients and choosing the method of treatment for each patient. Controversial issues were selected as clinical questions, and recommendations were made. Each recommendation is accompanied by a classification of the evidence and a classification of recommendation categories based on the consensus reached by the Guideline Committee members. Here, we present the English version of the JSCCR guidelines 2019.

Cannabidiol Overcomes Oxaliplatin Resistance by Enhancing NOS3- and SOD2-Induced Autophagy in Human Colorectal Cancer Cells.

Although oxaliplatin is an effective chemotherapeutic drug for colorectal cancer (CRC) treatment, patients often develop resistance to it. Therefore, a new strategy for CRC treatment is needed. The purpose of this study was to determine the effect of cannabidiol (CBD), one of the components of the cannabis plant, in overcoming oxaliplatin resistance in CRC cells. We established oxaliplatin-resistant cell lines, DLD-1 R and colo205 R, in CRC DLD-1 and colo205 cells. Autophagic cell death was induced when oxaliplatin-resistant cells were treated with both oxaliplatin and CBD. Additionally, phosphorylation of nitric oxide synthase 3 (NOS3) was increased in oxaliplatin-resistant cells compared to that in parent cells. Combined treatment with oxaliplatin and CBD reduced phospho-NOS3 levels and nitric oxide (NO) production and resulted in the production of reactive oxygen species (ROS) by reducing the levels of superoxide dismutase 2, an antioxidant present in the mitochondria, causing mitochondrial dysfunction. Taken together, these results suggest that elevated phosphorylation of NOS3 is essential for oxaliplatin resistance. The combination of oxaliplatin and CBD decreased NOS3 phosphorylation, which resulted in autophagy, by inducing the overproduction of ROS through mitochondrial dysfunction, thus overcoming oxaliplatin resistance.

Enhanced antitumor effect of cytotoxic T lymphocytes induced by dendritic cells pulsed with colorectal cancer cell lysate expressing α‑Gal epitopes

Colorectal cancer (CRC) is one of the most common types of gastrointestinal malignancy. Traditional therapeutic options for CRC exhibit a limited effect. Adoptive cellular therapy has emerged as a new treatment strategy for CRC. Dendritic cells (DCs) are potent antigen-presenting cells. Specific cytotoxic T lymphocytes (CTLs) activated by DCs pulsed with tumor lysate have been reported to be a safe and promising treatment approach for CRC. However, the antitumor effect of specific CTLs remains limited. The low immunogenicity of tumor-associated antigens (TAAs) is the main reason for this limited therapeutic effect. In the present study, α-gal epitopes were synthesized on the CRC cell line SW620 to increase the immunogenicity of TAAs. DCs were pulsed with α-gal-expressing tumor lysate and CTLs were activated by these DCs. The cytotoxicity of CTLs was measured in vitro. The results demonstrated that DCs pulsed with α-gal-expressing tumor lysate can increase the frequency of CD3+CD8+ CTLs and natural killer T cells, increase the level of tumor necrosis factor-α produced by CTLs and enhance the cytotoxicity of CTLs against tumor cells. Therefore, this novel approach may be an effective treatment strategy for patients with CRC.

Guar gum modified upconversion nanocomposites for colorectal cancer treatment through enzyme-responsive drug release and NIR-triggered photodynamic therapy

Multimodal therapeutic approach towards colorectal cancer (CRC) holds great promise. There is, however, no convincing strategy reported to date that employs a multimodal strategy in CRC treatment. The present study reports an intense green-emitting core–shell photoluminescent upconversion (CSGU) nanocrystal engineered to synergistically perform photodynamic and enzyme-triggered delivery of the chemotherapeutic agent for an enhanced therapeutic outcome on HT-29 colon carcinoma cells in vitro. The photodynamic activity is achieved by the energy transfer between CSGU and the chemically conjugated Rose Bengal (RB) molecules that are further protected by a mesoporous silica (MS) layer. The chemical assay demonstrates a remarkable FRET mediated generation of 1O2 under NIR (980 nm) excitation. The outermost MS layer of the nanoplatform is utilized for the loading of the 5FU anticancer drug, which is further capped with a guar gum (GG) polysaccharide polymer. The release of the 5FU is specifically triggered by the degradation of the GG cap by specific enzymes secreted from colonic microflora, which otherwise showed ‘zero-release behavior’ in the absence of any enzymatic trigger in various simulated gastro-intestinal (GI) conditions. Furthermore, the enhanced therapeutic efficacy of the nanoplatform (CSGUR-MSGG/5FU) was evaluated through in vitro studies using HT-29 CRC cell lines by various biochemical and microscopic assays by the simultaneous triggering effect of colonic enzyme and 980 nm laser excitation. In addition, the strong visible emission from the nanoplatform has been utilized for NIR-induced cellular bioimaging.

Calotropin activates YAP through downregulation of LATS1 in colorectal cancer cells.

Objectives: Calotropin (CTP), a natural product isolated from Calotropis gigantea, has been identified as a potential anticancer agent. In this study, we aimed to investigate the effect CTP on colorectal cancer and the role of Yes-associated protein (YAP) in CTP-inhibited cell proliferation.Methods: Cell viability and cell proliferation were detected by MTT and BrdU assay. Western blotting and immunofluorescence were performed to determine CTP-induced YAP dephosphorylation and nuclear localization. Western blotting, siRNA transfection and RT-PCR analysis were carried out to investigate the mechanisms of CTP-mediated YAP activation. The anti-tumor activities of CTP were observed in mice tumor models.Results: We demonstrated that CTP inhibits the proliferation of colorectal cancer cells both in vitro and in vivo. Moreover, we showed that CTP activates YAP in colorectal cancer cells. Mechanistically, CTP promotes LATS1 degradation via the ubiquitination/proteasome pathway, resulting in YAP dephosphorylation and nuclear localization, leading to induce YAP target genes expression in colorectal cancer cells. Inhibition of YAP activity enhances CTP-mediated inhibition of cell proliferation, suggesting that YAP plays a protective role in CTP-induced antiproliferative effect.Conclusion: Our results demonstrate that CTP markedly inhibits tumor growth and activates a protective role of YAP in colorectal cancer cells, indicating that combination of CTP and YAP targeting drugs may be a promising strategy for colorectal cancer treatment.

Thermosensitive Micelles Encapsulating Phenylalanine Ammonia Lyase Act as a Sustained and Efficacious Therapy Against Colorectal Cancer.

Colorectal cancer has become the third most commonly diagnosed cancer worldwide, which has posed challenges to current conventional therapies. Hence, we propose an alternative approach to the existing therapeutics for colorectal cancer treatment. In this work, we prepared thermosensitive micelles based on poly(ethylene glycol)-poly(caprolactone)poly(ethylene glycol) (PEG-PCL-PEG, PECE) copolymers (PAL-micelles) that were used to encapsulate phenylalanine ammonia lyase (PAL) as an in situ sustained drug delivery system. In vitro experiments suggested that PAL could inhibit the proliferation and induce apoptosis of tumor cells because the depletion of local phenylalanine blocked the synthesis of corresponding proteins. In addition, the release behavior In vitro and in vivo showed that PAL could be released from PAL-micelles in a controlled manner. Moreover, a significant inhibition of tumor growth was observed in the PAL-micellestreated xenograft mouse model compared to the control groups in vivo, but the systemic toxicity was not noteworthy. The antitumor efficacy was further confirmed by histological analysis of the tumor tissues with hematoxylin and eosin (H&E) and Ki-67 staining. The above results demonstrated that the PAL-micelles system could be considered an alternative strategy for colorectal cancer treatment.

The capability and potential of new forms of personalized colon cancer treatment: Immunotherapy and Photodynamic Therapy.

PDT can interfere with cytokine-mediated responses that play an important role in the processes of cancer progression, tumor angiogenesis and metastasis. Therefore, based on the identification of these cancer biomarkers, the therapy of combining various forms of treatment, including immunotherapy and PDT, may be a justified strategy for colorectal cancer treatment that focuses on individualized comprehensive therapy. We reviewed the major approaches on the use of immunotherapy in colorectal cancer, with the special regard to photodynamic therapy, its immunological effect and new oncological treatment directions, connected with adjuvant immunotherapy including use of nanoparticles. Databases such as PubMed, ScienceDirect and Springer were utilized to search the literature for relevant articles. To review studies of the immunotherapy in colon cancer and immune response to PDT. Based on the identification of immunological cancer biomarkers, the therapy of combining various forms of treatment, including immunotherapy and PDT, may be a justified strategy for colorectal cancer treatment that focuses on individualized comprehensive therapy.

Ubiquitin specific peptidase 5 regulates colorectal cancer cell growth by stabilizing Tu translation elongation factor

Ubiquitin specific peptidase 5 (USP5) is a ubiquitous expressed deubiquitinating enzyme (DUB). It has been shown involved in DNA repair, apoptosis, inflammation, and tumor cell growth. However, the function and molecular mechanism of USP5 in colorectal cancer (CRC) are still unclear. In the present study, we asked how it affected the growth of colorectal cancer cells.Methods: A shRNA-based high-content screening was performed to identify DUBs affecting the growth of CRC cells. CCK-8 assay and xenografts were used to assess CRC cell growth, survival and tumorigenesis. RT-qPCR, immunoblotting and immunohistochemistry were carried out to quantitate USP5 expression in CRC tissues and cell lines. Immunoprecipitation and mass spectrometry analysis were performed to identify USP5-interacting proteins. Cycloheximide chase was performed to assess Tu translation elongation factor (TUFM) stability. Dual luciferase reporter assay was utilized for USP5 promoter analysis.Results: We found that USP5 was highly expressed in a group of primary CRC tissues, and the increased USP5 was correlated with clinical stages and shorter overall survival. While USP5 knockdown effectively inhibited CRC cell growth, overexpressed USP5 promoted the growth of CRC cells and made them more resistant to doxorubicin (DOX). TUFM was discovered as a substrate of USP5. USP5 deubiquitinated TUFM and increased its level in CRC cells. Enforced expression of TUFM was able to alleviate the growth inhibition induced by USP5 knockdown. Further analyses showed that EBF transcription factor 1 (EBF1) was a major regulator for USP5 transcription, and DOX inhibited EBF1-USP5-TUFM axis in CRC cells.Conclusions: USP5 was required for CRC cells and promoted their growth and resistance to chemotherapeutics. TUFM was a USP5 deubiquitinating substrate that mediated the cellular effects of USP5. The transcription of USP5 was regulated by EBF1. Thus, targeting EBF1-USP5-TUFM axis is a potential novel strategy for CRC treatment.

BRD4 Inhibitor AZD5153 Suppresses the Proliferation of Colorectal Cancer Cells and Sensitizes the Anticancer Effect of PARP Inhibitor.

Background: Bromodomain-containing protein 4(BRD4) is reported to play a vital role in the development of numerous malignant diseases, which is considered as a promising target for cancer therapy. AZD5153, a novel specific BRD4 inhibitor, showed potent anticancer effects in several cancer types, but its therapeutic potential has not been fully evaluated in colorectal cancer cells.Objective: We sought to evaluate the therapeutic potential of BRD4 inhibition of by AZD5153 and its combined anticancer cancer effect with PARP inhibitor BMN673 in vitro and in vivo in colorectal cancer.Methods: We analyzed The Cancer Genome Atlas (TCGA) database to investigate BRD4 expression in colorectal cancer patient. Clonogenic assays 、MTT assays and PI/Annexin V staining were used to determine the effect of AZD5153 and BMN673 and combination therapy on cell viability and apoptosis induction. Western blotting was applied to detect relevant molecules changes. Propidium iodide staining was performed to examine cell cycle distributions after monotherapy or combination therapy. Nude mice xenograft model was generated to confirm the therapeutic effect of AZD5153 and BMN673 combination in vivo, and IHC staining was used to detect the expression level of BRD4 and related markers in colorectal patient and xenograft.Results: Analysis of TCGA database indicated that BRD4 was overexpressed in colorectal cancer patient. The clonogenic and MTT assays and PI/Annexin V staining demonstrated that AZD5153 significantly suppressed cell proliferation and induced apoptosis in colorectal cancer cells HCT116 and LoVo. Western blotting showed that AZD5153 inhibited the expression of c-Myc and increased expression of the apoptosis markers, cleaved caspase-3 and poly(ADP-ribose) polymerase (PARP), besides, we found that BRD4 knockdown could also inhibited cell proliferation and induced cell apoptosis. Moreover, AZD5153 inhibited the expression of Wee1 and impaired G2M cell cycle checkpoint, thus sensitized the anticancer effect of BMN673 in vitro and in vivo.Conclusion: Our data revealed that AZD5153suppressed the proliferation of colorectal cancer cells and sensitized them to the anticancer effect of the PARP inhibitor BMN673 via Wee1 inhibition in vitro and in vivo. This suggested that targeting BRD4 might be a valuable strategy for colorectal cancer treatment.

Astragalus saponins inhibit cell growth, aerobic glycolysis and attenuate the inflammatory response in a DSS-induced colitis model.

Recent studies have reported that Astragalus saponins (AST), extracted from the medicinal plant Astragalus membranaceus, possess anti‑tumor and apoptosis‑inducing abilities on various types of human cancer in vitro and in vivo. However, limited studies have explored how AST impacts glucose metabolism and growth conditions in vitro. The present study aimed to explore cell growth, proliferation, apoptosis and a series of glycolysis metabolic alterations associated with AST treatment in colorectal cancer (CRC) cells. MTT, a colony formation assay and flow cytometry demonstrated that AST dose‑dependently inhibited cell viability and induced apoptosis. Glucose uptake and lactate production measurements revealed that AST could inhibit glycolysis metabolism and lactate production. Reverse transcription‑quantitative polymerase chain reaction and western blot analysis identified that the expression levels of glycolytic enzymes were decreased by AST treatment in CRC cells. To uncover the possible impact of AST on inflammation and glucose metabolism in vivo, a dextran sulfate sodium (DSS)‑induced colitis mouse model was established. Notably, AST could inhibit growth and glycolysis metabolism in CRC cells in vitro, and attenuate the inflammatory response and tumor‑like aerobic glycolysis in the DSS‑induced mouse model. The findings indicated that AST may have the capacity to resist tumor‑associated inflammation and maintain normal glucose homeostasis, suggesting that AST could be a novel therapeutic strategy in CRC treatment.

Prevention of Wogonin on Colorectal Cancer Tumorigenesis by Regulating p53 Nuclear Translocation.

The tumor suppressor protein p53 plays an important role in the development and progression of colon cancer, and the subcellular organelle localization directly affects its function. Wogonin (5,7-dihydroxy-8-methoxyflavone), a mono-flavonoid extracted from root of Scutellaria baicalensis Georgi, possesses acceptable toxicity and has been used in colorectal cancer (CRC) chemoprevention in pre-clinical trials by oncologist. However, the underlying anti-colon cancer mechanisms of wogonin are not yet fully understood. In the present study, the effect of wogonin on the initiation and development of colitis-associated cancer through p53 nuclear translocation was explored. AOM-DSS CRC animal model and human CRC HCT-116 cell model were used to evaluate the in vivo and in vitro anti-colon cancer action of wogonin. We observed that wogonin showed a dramaticlly preventive effect on colon cancer. Our results showed that wogonin caused apoptotic cell death in human CRC HCT-116 cell through increased endoplasmic reticulum (ER) stress. Meanwhile, excessive ER stress facilitated the cytoplasmic localization of p53 through increasing phosphor-p53 at S315 and S376 sites, induced caspase-dependent apoptosis and inhibited autophagy. Furthermore, we verified the chemoprevention effect and toxicity of wogonin in vivo by utilizing an AOM-DSS colon cancer animal model. We found that wogonin not only reduced tumor multiplicity, preserved colon length to normal (6.79 ± 0.34 to 7.41 ± 0.56, P < 0.05) but also didn’t induce side effects on various organs. In conclusion, these results explain the anti-tumor effect of wogonin in CRC and suggest wogonin as a potential therapeutic candidate for the therapeutic strategy in CRC treatment.

Interleukin-17 promotes the development of cisplatin resistance in colorectal cancer.

Cisplatin (DDP)-based anticancer therapy is an important chemotherapeutic strategy for the treatment of colorectal cancer. However, its beneficial effect is largely compromised by adverse reactions, and more importantly, by the development of drug resistance. Therefore, it is crucial to determine the potential mechanism underlying the development of DDP resistance in colorectal cancer. Interleukin-17 (IL-17) is a proinflammatory cytokine that has been found to serve an important role in the host defense during cancer development. It has been suggested that IL-17 is key to promoting the development of resistance to DDP in several major types of cancer. However, the role of IL-17 in DDP resistance in colorectal cancer has not been extensively investigated. In the present study, it was observed that IL-17 was significantly upregulated in colorectal tumor samples, compared with the adjacent tissues. Furthermore, IL-17 was found to promote the viability of HCT116 colorectal cells treated with DDP, whilst blocking IL-17 signaling leading to HCT116 cell apoptosis. IL-17 was also shown to regulate the expression of several apoptosis-related proteins, including phosphorylated-protein kinase B (p-Akt), apoptosis regulator BAX (Bax), apoptosis regulator Bcl-2 (Bcl-2) and serine/threonine-protein kinase mTOR (mTOR). These findings indicated that IL-17 facilitates the development of DDP resistance in colorectal cancer by inhibiting cancer cell apoptosis through targeting p-Akt, Bax, Bcl-2 and mTOR. Overall, the findings of the present study suggest that a combination of DDP and an IL-17 inhibitor may prove to be a highly efficient strategy for colorectal cancer treatment.

A novel microfluidic liposomal formulation for the delivery of the SN-38 camptothecin: characterization and in vitro assessment of its cytotoxic effect on two tumor cell lines.

PurposeIrinotecan (CPT-11) and SN-38 – its active metabolite – are alkaloid-derived topoisomerase I interactive compounds widely used in various cancer therapy protocols. To solve the problems associated with the instability of their lactone ring at physiological pH and with the extreme insolubility of SN-38, the development of delivery carriers (eg, liposomes) has been considered a subject of unquestionable medical interest. This article focuses on the development of an alternative protocol to the classical lipid-film hydration procedures to obtain a pharmaceutical formulation for SN-38.MethodsSN-38-loaded liposomes (SN-38lip) were produced by microemulsification, without a prior lipid-film preparation step, and characterized by different methods. Formulation parameters were determined by photon correlation spectroscopy, and the SN-38 entrapment efficiency was evaluated by absorbance spectroscopy. SN-38lip was obtained as a dry, white powder by lyophilization. MTT and LDH assays were conducted to assess the cytotoxic effect of SN-38, both in liposomal (SN-38lip) and solubilized form (SN-38sol); flow cytometry was used to quantify SN-38 uptake and to analyze cell-cycle phase distribution after drug exposure.ResultsMicrofluidic, stable, and controlled sized, negatively charged liposomes, with high SN-38 incorporation efficiency into egg yolk phosphatidylcholine (EPC)/L-α-dioleoyl-phospathidylserine (DOPS) (9:1) vesicles (SN-38lip), were prepared. A lyophilized powder of SN-38lip, easily reconstitutable while retaining physicochemical parameters, was finally obtained. The efficacy of SN-38lip was assessed by in vitro studies with two tumor cell lines (HeLa and Caco-2) and compared with that of SN-38sol. It demonstrated the highest uptake of SN-38lip, in accordance with its highest cytotoxicity effect, in comparison with that of SN-38sol. In addition, different cell-cycle alterations were induced in both cell lines by the liposomal formulation.ConclusionThe results highlight the potential usefulness of the procured SN-38 liposomal formulation and provide the basis for conducting in vivo studies that allow the development of alternative strategies for colorectal cancer treatment.

Anticancer activities of a benzimidazole compound through sirtuin inhibition in colorectal cancer.

This study aims to investigate the mode of action of a novel sirtuin inhibitor (BZD9L1) and its associated molecular pathways in colorectal cancer (CRC) cells. BZD9L1 was tested against metastatic CRC cell lines to evaluate cytotoxicity, cell cycle and apoptosis, senescence, apoptosis related genes and protein expressions, as well as effect against major cancer signaling pathways. BZD9L1 reduced the viability, cell migration and colony forming ability of both HCT 116 and HT-29 metastatic CRC cell lines through apoptosis. BZD9L1 regulated major cancer pathways differently in CRC with different mutation profiles. BZD9L1 exhibited anticancer activities as a cytotoxic drug in CRC and as a promising therapeutic strategy in CRC treatment.

Abstract 3495: Trip13, a target of miR192, facilitates colorectal cancer progression through WNT/β-catenin signaling

Abstract Most colorectal cancers (CRCs) exhibit genomic instability or chromosomal instability (CIN) in the form of aneuploidy. These aberrations are associated with chromosomal gains or losses. In human malignances, levels of a member of the AAA-ATPases family, TRIP13, correlate with CIN. In the present study, we investigated the expression and biological function of TRIP13 in CRC. In silico gene expression profiling using the UALCAN (http://ualcan.path.uab.edu/) web portal showed elevated TRIP13 expression in CRCs as compared to normal/benign colonic epithelial tissues. Studies employing immunoblot analyses confirmed elevated expression of the TRIP13 protein in CRC tissues compared to their matched normal/benign colorectal tissues. Concurrent immunohistochemical analysis of tissue microarrays, containing normal and tumor tissues, further validated cytoplasmic TRIP13 expression in CRCs as compared to their contiguous normal/benign epithelial components. To understand the functional significance of TRIP13 in CRCs, particularly in regard to progression of cancer cells, experiments were performed by utilizing lentivirus-mediated TRIP13 silencing in CRC cell lines that express high levels of TRIP13. Depletion of TRIP13 impeded cell proliferation, colony formation, invasion, cell motility, and spheroid-forming capacity. TRIP13 depletion also showed suppression of EGFR activation and WNT/β-catenin signaling. Furthermore, bioinformatic analysis revealed that TRIP13 is a predicted target of miR192. Dual-luciferase reporter assays showed that miR192 binds to the 3' UTR of TRIP13. Also, overexpression of miR192 in HCT116 cells lowered TRIP13 expression and reduced cell proliferation, colony formation, and invasion, suggesting that it is a tumor suppressor. Thus, these findings demonstrate a function of TRIP13 in the progression of CRCs and indicate that TRIP13 inhibition by small molecules is a possible strategy for treatment of CRC. Citation Format: Sumit Agarwal, Balabhadrapatruni V. Chakravarthi, Darshan S. Chandrashekar, Rong Jun Guo, Pran Datta, Sooryanarayana Varambally, Upender Manne. Trip13, a target of miR192, facilitates colorectal cancer progression through WNT/β-catenin signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3495.

PO-203 A novel member in the β-catenin destruction complex: may MAPK14/P38α foster new therapeutic approaches in colorectal cancer?

IntroductionOne of the most commonly deregulated signalling pathways in colorectal cancer (CRC) is the Wnt cascade, which is controlled by APC. APC regulates β-catenin levels, thereby modulating the transcriptional activity of the TCF/LEF transcription factors. High levels of nuclear β-catenin lead to constitutive activation of the Wnt pathway, loss of normal cellular architecture and neoplastic transformation. Previous reports indicate that Wnts are capable of activating p38 MAPKs. A few older studies carried out in other tissues provided evidence that Wnt3a could activate p38 suggesting that the p38 pathway may feed into the canonical Wnt/β-catenin pathway at least at the level of GSK3β. We recently showed that p38α is required to maintain CRC metabolism and survival, as its inhibition leads to activation of FoxO3A, autophagy, cell death and tumour growth reduction both in vitro and in vivo.Material and methodsWe performed extensive characterisation of the functional interaction between p38 and the APC/β-catenin/GSK3β complex (co-localization analysis by confocal microscopy and co-immunoprecipitation studies) in several cell lines in vitro and in the APCMin/+ mouse preclinical model in vivo.Results and discussionsOur data showed that CRC cells have higher levels of activated p38 than their normal counterparts, and experiments using kinase-specific inhibitors revealed that these cells are ‘addicted’ to p38 activity. Interestingly, p38α blockade reduced the size and number of adenomas in the small bowel of APCMin/+ mice. Significant results were obtained in vivo by co-immunoprecipitation analysis of tissues from normal mice and APCMin/+ mice treated or not with AOM. Our findings confirmed the presence of p38α in APC/β-catenin/GSK3β complexes in CRC cells. Importantly, p38α co-localised with β-catenin in both normal and cancer cells; however, these proteins were confined to the cytoplasm in colonocytes, while they occupied discrete nuclear regions in CRC cells. These data were further corroborated by the inhibitory effect of p38α blockade on β-catenin-responsive genes (i.e. c-Myc, cyclin D1/2). Characterisation of this novel functional interaction was also extended with chromatin immunoprecipitation experiments.ConclusionIdentification of p38α as a novel member of the APC/β-catenin/GSK3β complex could help elucidate mechanisms contributing to human colon tumour pathogenesis and allow for the development of new strategies for CRC treatment.

Abstract 4181: Simultaneous inhibition of the Wnt/B-catenin and Ras pathways by KY1022 effectively suppresses tumor initiation and progression of colorectal cancer

Abstract APC (80-90%) and K-Ras (40-50%) mutations frequently occur in human colorectal cancer (CRC) and these mutations cooperatively accelerate tumorigenesis including metastasis. In addition, both B-catenin and Ras levels are highly increased in CRC, especially in metastatic CRC (mCRC). Targeting these signaling pathways may therefore be an ideal strategy for treating mCRC; however, therapeutics targeting both of these pathways have not been developed because the mechanisms regulating these pathways are not well understood. Based on our recent identification of the B-catenin destruction complex-mediated Ras protein stability mechanism, we screened a small-molecule library to identify compounds that destabilize both B-catenin and Ras proteins via inhibition of the Wnt/B-catenin pathway. Among the effective small molecules destabilizing both B-catenin and Ras proteins via inhibition of the Wnt/β-catenin pathway, we characterized KY1022, a small molecule that most effectively inhibits EMT, an initial process of metastasis. As shown by in vitro and in vivo studies using APCMin/+/K-RasG12DLA2 mice, KY1022 effectively suppressed the development of mCRC at an early stage of tumorigenesis. Our results suggest that a small molecular approach degrading both B-catenin and Ras via inhibition of the Wnt/B-catenin signaling would be an ideal strategy for treatment of CRC including mCRC. Citation Format: Eun Ji Ro, Jeong-Ha Hwang, Yong-Hee Cho, Kang-Yell Choi. Simultaneous inhibition of the Wnt/B-catenin and Ras pathways by KY1022 effectively suppresses tumor initiation and progression of colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4181.

Iron chelation inhibits cancer cell growth and modulates global histone methylation status in colorectal cancer.

Colorectal cancer (CRC) is one of the most common malignancies worldwide, and new treatment strategies for CRC are required because of the existing chemotherapy resistance. Iron chelators, which have been used widely for the treatment of iron-overload disease, were reported to exert anti-proliferative effects in cancer. However, the role of iron chelation in CRC was largely unknown. In this study, we found that the iron chelator DFO inhibited CRC cell growth significantly. In addition, the gene expression profile was greatly changed by DFO treatment, and many cell growth-related genes were dysregulated. Further study showed that DFO induced a significant increase in global histone methylation in CRC cells. However, the levels of histone methyltransferases and histone demethylases did not change in response to DFO treatment, implying that the enzymatic activity of these enzymes might be regulated by iron chelation. In conclusion, this study reveals a novel role for DFO in CRC cell growth, and is the first to demonstrate that global histone methylation is modulated by iron chelation in CRC cells.

Recent updates in the surgical treatment of colorectal cancer.

Because of recent advances in medical technology and new findings of clinical trials, treatment options for colorectal cancer are evolutionally changing, even in the last few years. Therefore, we need to update the treatment options and strategies so that patients can receive optimal and tailored treatment. The present review aimed to elucidate the recent global trends and update the surgical treatment strategies in colorectal cancer by citing the literature published in the last 2 years, namely 2016 and 2017. Although laparoscopic surgery is still considered the most common approach for the treatment of colorectal cancer, new surgical technologies such as transanal total mesorectal excision, robotic surgery, and laparoscopic lateral pelvic lymph node dissection are emerging. However, with the recent evidence, superiority of the laparoscopic approach to the open approach for rectal cancer seems to be controversial. Surgeons should notice the risk of adverse outcomes associated with unfounded and uncontrolled use of these novel techniques. Many promising results are accumulating in preoperative and postoperative treatment including chemotherapy, chemoradiotherapy, and targeted therapy. Development of new biomarkers seems to be essential for further improvement in the treatment outcomes of colorectal cancer patients.