Properties Of Colorectal Cancer Research Articles

Abstract 1566: Cancer metastasis and stemness: The metastasis-inducer MACC1 regulates LGR5 to promote cancer stem cell-like properties in colorectal cancer

Abstract Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. The high mortality is directly associated with metastatic disease which is thought to be initiated by colon cancer stem cells according to cancer stem cell (CSC) model. Consequently, early identification of those patients who are at high risk for metastasis is crucial for improved treatment and patient outcome. Metastasis-associated in colon cancer 1 (MACC1) is a novel prognostic biomarker for tumor progression and metastasis formation independent of tumor stage. We previously showed an involvement of MACC1 in cancer stemness in the mouse intestine of our transgenic mouse models. However, the expression of MACC1 in human CSCs and possible implications remain elusive. Here, we explored the molecular mechanisms by which MACC1 regulates stemness and CSC-associated invasive phenotype based on patient-derived 3D cell culture models (PD3D), patient-derived xenografts (PDX) and human CRC cell lines. We showed that CD44-enriched CSCs from PD3D models express significantly higher levels of MACC1 and display higher tumorigenicity in immunocompromised mice. Similarly, RNA sequencing performed on PD3D and PDX models demonstrated significantly increased MACC1 expression in ALDH1(+) CSCs, highlighting its involvement in cancer stemness. We further showed the correlation of MACC1 with CSC markers CD44, NANOG and LGR5 in PD3D models as well as established cell lines. Additionally, MACC1 increased stem cell gene expression, clonogenicity and sphere formation. Strikingly, we showed that MACC1 binds as a transcription factor to the LGR5 gene promoter uncovering the long-known CSC marker LGR5 as novel essential signaling mediator used by MACC1 to induce CSC-like properties in human CRC patients. Our in vitro findings were further substantiated by significant positive correlation of MACC1 and LGR5 in CRC cell lines as well as CRC patient tumors. Taken together, this study indicates that the metastasis-inducer MACC1 act as a cancer stem cell-associated marker. Interventional approaches targeting MACC1 would potentially improve further targeted therapies for colorectal cancer patients to eradicate CSCs, prevent cancer recurrence and distant metastasis formation. Citation Format: Müge Erdem, Kyung Hwan Lee, Markus Hardt, Joseph Regan, Dennis Kobelt, Wolfgang Walther, Christian Regenbrecht, Ulrike S. Stein. Cancer metastasis and stemness: The metastasis-inducer MACC1 regulates LGR5 to promote cancer stem cell-like properties in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1566.

A non-immunotoxic exopolysaccharide with anticancer effect in colorectal cancer isolated from Lacticaseibacillus rhamnosus ACS5 strain

Recent studies demonstrated the potential of exopolysaccharides (EPS) produced by LAB (lactic acid bacteria), to be used in different fields. In our study, L-EPS-ACS5 from Lacticaseibacillus rhamnosus ACS5 strain isolated from Ayvalık Cunda Sepet Cheese, one of the traditional cheeses of Turkey, showed antiproliferative effect in a time-dependent manner in human colon cancer (HT-29) cell line compared to healthy control line (L929). This effect was also confirmed by colony formation analysis. Apoptotic changes were investigated at molecular level using qPCR, Western blot and it was determined that the relevant L-EPS induced apoptosis by increasing Bax, Caspase 3, and 9 expression while reducing the Bcl-2 expression. These changes were confirmed by observations done at nuclear and cellular morphology level using a fluorescence microscope (Hoescht 33258) and TEM. In addition, the immunostimulatory activity of the relevant L-EPS was evaluated in terms of proliferation, phagocytosis ability and nitric oxide (NO) production parameters in the RAW 264.7 macrophage cell line. The increase in proliferative activity was not significant, and in parallel with these results, the differences in the control and application groups as a result of 'phagocytic activity and NO production analyzes' were also not significant. However, L-EPS-ACS5 did not show immunotoxic/cytotoxic activity in macrophage cells (% viability >70). All these cellular and molecular evidences indicate that L-EPS-ACS5 may be a good alternative to synthetic anti-cancer agents with its anticancer effect and non-immunotoxic properties in colorectal cancer.

MACC1 Regulates LGR5 to Promote Cancer Stem Cell Properties in Colorectal Cancer

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. The high mortality is directly associated with metastatic disease, which is thought to be initiated by colon cancer stem cells, according to the cancer stem cell (CSC) model. Consequently, early identification of those patients who are at high risk for metastasis is crucial for improved treatment and patient outcomes. Metastasis-associated in colon cancer 1 (MACC1) is a novel prognostic biomarker for tumor progression and metastasis formation independent of tumor stage. We previously showed an involvement of MACC1 in cancer stemness in the mouse intestine of our MACC1 transgenic mouse models. However, the expression of MACC1 in human CSCs and possible implications remain elusive. Here, we explored the molecular mechanisms by which MACC1 regulates stemness and the CSC-associated invasive phenotype based on patient-derived tumor organoids (PDOs), patient-derived xenografts (PDXs) and human CRC cell lines. We showed that CD44-enriched CSCs from PDO models express significantly higher levels of MACC1 and LGR5 and display higher tumorigenicity in immunocompromised mice. Similarly, RNA sequencing performed on PDO and PDX models demonstrated significantly increased MACC1 expression in ALDH1(+) CSCs, highlighting its involvement in cancer stemness. We further showed the correlation of MACC1 with the CSC markers CD44, NANOG and LGR5 in PDO models as well as established cell lines. Additionally, MACC1 increased stem cell gene expression, clonogenicity and sphere formation. Strikingly, we showed that MACC1 binds as a transcription factor to the LGR5 gene promoter, uncovering the long-known CSC marker LGR5 as a novel essential signaling mediator employed by MACC1 to induce CSC-like properties in human CRC patients. Our in vitro findings were further substantiated by a significant positive correlation of MACC1 with LGR5 in CRC cell lines as well as CRC patient tumors. Taken together, this study indicates that the metastasis inducer MACC1 acts as a cancer stem cell-associated marker. Interventional approaches targeting MACC1 would potentially improve further targeted therapies for colorectal cancer patients to eradicate CSCs and prevent cancer recurrence and distant metastasis formation.

ZNF217-activated Notch signaling mediates sulforaphane-suppressed stem cell properties in colorectal cancer

Cancer stem cells (CSCs) are known to contribute to the progression of colorectal cancer (CRC). However, understanding of the molecular mechanisms and key factors involved in CRC is still insufficient to identify therapeutic targets against colorectal CSCs. In an effort to identify such mechanisms, we conducted bioinformatics analyses to evaluate the expression patterns in tumor and normal colorectal tissues, leading us to focus on the role of the ZNF217/Notch1 axis in mediating stem cell properties in CRC. Our findings revealed that ZNF217 overexpression activated self-renewal ability, expression of colorectal CSC markers, and Notch signaling in CRC. Dual-luciferase reporter assay suggested a role for ZNF217 in targeting Notch1 to activate Notch signaling. We observed that the promotional effects of Notch signaling, as well as CSC markers, under ZNF217 overexpression were attenuated after Notch1 knockdown. In addition to in vitro data, our in vivo results confirmed the inhibitory effect of sulforaphane on the tumorigenicity of CSCs, depicted the suppressive role of sulforaphane on colorectal CSCs mediated by the ZNF217/Notch1 axis, thereby providing new targetable vulnerabilities and therapeutic strategies for CRC.

M6A modified BACE1-AS contributes to liver metastasis and stemness-like properties in colorectal cancer through TUFT1 dependent activation of Wnt signaling

BackgroundLiver metastasis is one of the most important reasons for high mortality of colorectal cancer (CRC). Growing evidence illustrates that lncRNAs play a critical role in CRC liver metastasis. Here we described a novel function and mechanisms of BACE1-AS promoting CRC liver metastasis.MethodsqRT-PCR and in situ hybridization were performed to examine the BACE1-AS level in CRC. IGF2BP2 binding to m6A motifs in BACE1-AS was determined by RIP assay and S1m-tagged immunoprecipitation. Transwell assay and liver metastasis mice model experiments were performed to examine the metastasis capabilities of BACE1-AS knockout cells. Stemness-like properties was examined by tumor sphere assay and the expression of stemness biomarkers. Microarray data were acquired to analyze the signaling pathways involved in BACE1-AS promoting CRC metastasis.ResultsBACE1-AS is the most up-regulated in metastatic CRC associated with unfavorable prognosis. Sequence blast revealed two m6A motifs in BACE1-AS. IGF2BP2 binding to these two m6A motifs is required for BACE1-AS boost in metastatic CRC. m6A modified BACE1-AS drives CRC cells migration and invasion and liver metastasis both in vitro and in vivo. Moreover, BACE1-AS maintains the stemness-like properties of CRC cells. Mechanically, BACE1-AS promoted TUFT1 expression by ceRNA network through miR-214-3p. CRC patients with such ceRNA network suffer poorer prognosis than ceRNA-negative patients. Depletion of TUFT1 mimics BACE1-AS loss. BACE1-AS activated Wnt signaling pathway in a TUFT1 dependent manner. BACE1-AS/miR-214-3p/TUFT1/Wnt signaling regulatory axis is essential for CRC liver metastasis. Pharmacologic inhibition of Wnt signaling pathway repressed liver metastasis and stemness-like features in BACE1-AS over-expressed CRC cells.ConclusionOur study demonstrated BACE1-AS as a novel target of IGF2BP2 through m6A modification. m6A modified BACE1-AS promotes CRC liver metastasis through TUFT1 dependent activation of Wnt signaling pathway. Thus, targeting BACE1-AS and its downstream Wnt signaling pathways may provide a new opportunity for metastatic CRC intervention and treatment.

Dihydroartemisinin inhibited stem cell-like properties and enhanced oxaliplatin sensitivity of colorectal cancer via AKT/mTOR signaling.

Colorectal cancer (CRC) is a common tumor with high morbidity and mortality. The use of oxaliplatin (L-OHP) as a first-line treatment for CRC is limited due to chemoresistance. Growing evidence have revealed that the existence of cancer stem-like cells (CSLCs) is one of the important reasons for drug resistance and recurrence of cancers. Dihydroartemisinin (DHA), a derivative of artemisinin, has showed anticancer effects on a variety of malignancies, in addition to its antimalarial effects. However, the effect and mechanism of DHA on CSLCs and chemosensitivity in CRC cells remains unclear. In this study, we found that DHA inhibited cell viability in HCT116 and SW620 cells. Moreover, DHA decreased cell clonogenicity, and improved L-OHP sensitivity. Furthermore, DHA treatment attenuated tumor sphere formation, and the expressions of stem cell surface marker (CD133 and CD44) and stemness-associated transcription factor (Nanog, c-Myc, and OCT4). Mechanistically, the present findings showed that DHA inhibited of AKT/mTOR signaling pathway. The activation of AKT/mTOR signaling reversed DHA-decreased cell viability, clonogenicity, L-OHP resistance, tumor sphere, and expressions of stemness-associated protein in CRC. The inhibitory effect of DHA on tumorigenicity of CRC cells has also been demonstrated in BALB/c nude mice. In conclusion, this study revealed that DHA inhibited CSLCs properties in CRC via AKT/mTOR signaling, suggesting that DHA may be used as a potential therapeutic agent for CRC.

Inorganic pyrophosphatase 1 activates the phosphatidylinositol 3-kinase/Akt signaling to promote tumorigenicity and stemness properties in colorectal cancer

Colorectal cancer (CRC) is a common malignant tumor of the human digestive tract. Inorganic pyrophosphatase 1 (PPA1) plays an imperative role in the advancement of malignant tumors, but its function in CRC is ill-defined. In this study, we inspected the functions of PPA1 in CRC. The abundance of PPA1 in CRC tissues was analyzed by utilizing publicly available data from the The Cancer Genome Atlas and Human Protein Atlas project. Cell counting kit-8 assay and 5-ethynyl-2′-deoxyuridine assay were used to evaluate the viability and proliferation of CRC cells. Bioinformatics analysis was used to forecast the PPA1 related genes and signal pathways in CRC. The protein expression was examined by western blot. The xenograft model was implemented to determine the influence of PPA1 in CRC in vivo. Proliferating cell nuclear antigen, CD133, and CD44 contents in xenograft tumors were evaluated by immunohistochemistry. In the present study, we found that the PPA1 content was heightened in CRC, and the diagnostic value of PPA1 in CRC was enormous. Overexpression of PPA1 enhanced cell proliferation and stemness properties in CRC cells, while downregulation of PPA1 had the opposite effects. PPA1 promoted the activation of the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Activation of the PI3K/Akt signaling reversed the effect of PPA1 silencing on cell proliferation and stemness properties in CRC cells. Silencing of PPA1 reduced xenograft tumor growth via modulating the PI3K/Akt signaling pathway in vivo. In conclusion, PPA1 promoted cell proliferation and stemness properties in CRC by activating the PI3K/Akt signaling pathway.

Abstract 2439: RPL27 augments growth and stemness properties in colorectal cancer through PLK1 signaling

Abstract Background: In 2020, colorectal cancer (CRC) had the second highest mortality rate worldwide and was the third most common cancer type among various carcinomas, accounting for 10.0% and 9.4% of all carcinomas, respectively. Although the expression of ribosomal protein L27 (RPL27) is upregulated during CRC development, oncogenic roles of RPL27 have not yet been elucidated. We aimed in this study to investigate the effect of RPL27 targeting on CRC growth and whether RPL27 gained an extra-ribosomal function during CRC development. Methods: Human CRC cell lines, HCT116 and HT29, were transfected with RPL27-specific siRNA and tested for growth inhibition and apoptotic induction using MTS, FACS and Western blotting. To obtain insights into the molecular changes in response to RPL27 knockdown, global changes in gene expression were examined using RNA sequencing. Results: We observed that inhibition of RPL27 expression suppresses CRC cell growth and long-term colony formation through an induction of apoptotic cell death. Targeting RPL27 also significantly inhibited the growth of human CRC xenografts in nude mice. Noticeably, polo-like kinase 1 (PLK1), which is known to play an important role in mitotic cell cycle progression and stemness, was commonly down-regulated in both HCT116 and HT29 cells with RPL27 depletion. Western blot analysis confirmed that RPL27 silencing reduces the levels of PLK1 protein and G2/M-associated regulators, such as p-CDC25C, CDK1, and cyclin B1. Reflecting these molecular responses, knockdown of RPL27 reduced the migration and invasion abilities of CRC cells. In terms of CSC phenotypic changes, RPL27 knockdown suppressed sphere forming capacity of isolated CD133+ CSC population accompanying with the reduction in CD133 and PLK1 levels. Conclusion: Taken together, these findings indicate that RPL27 contributes to promotion of CRC growth and stemness through PLK1 signaling and that targeting RPL27 could be a next-line therapeutic strategy for both primary CRC treatment and prevention of metastasis and/or recurrence. Citation Format: Keon Uk Park, Ilseon Hwang, Hun Mo Ryoo, Yun-Han Lee, So-Young Park. RPL27 augments growth and stemness properties in colorectal cancer through PLK1 signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2439.

AKT1 phosphorylates RBM17 to promote Sox2 transcription by modulating alternative splicing of FOXM1 to enhance cancer stem cell properties in colorectal cancer cells.

Colorectal cancer (CRC) is one of the leading causes of cancer-related death worldwide. The existence of cancer stem cells (CSC) causes tumor relapses, metastasis, and resistance to conventional therapy. Alternative splicing has been shown to affect physiological and pathological processes. Accumulating evidence has confirmed that targeting alternative splicing could be an effective strategy to treat CRC. Currently, the role of alternative splicing in the regulation of CSC properties in CRC has not been elucidated. Here, we show that RBM17 displays oncogenic roles in CRC cells. RBM17 enhances cell proliferation and reduces chemotherapeutic-induced apoptosis in CRC cells. Besides, RBM17 increases CD133 positive and ALDEFLUOR positive populations and promotes sphere formation in CRC cells. In mechanism studies, we found that FOXM1 is critical for RBM17 enhanced CSC properties. Moreover, FOXM1 alternative splicing is essential for RBM17 enhanced CSC properties in CRC cells. Additionally, RBM17 enhances CSC characteristics by controlling FOXM1 expression to promote Sox2 expression. Furthermore, AKT1 works as an upstream kinase to control RBM17-mediated FOXM1 alternative splicing and enhancement of CSC properties in CRC cells. Our study reveals that AKT1-RBM17-FOXM1-Sox2 axis could be a potential target for modulating alternative splicing to reduce CSC properties in CRC cells.

Abstract B021: Claudin-1 expression promotes chemoresistance and cancer stem cell characteristics in colorectal cancer

Abstract Background: Claudins are integral components of tight junction complexes. Beyond just passive cell adhesion molecules, they influence structural dynamics, molecular trafficking, and important cell signaling pathways. Claudins are often dysregulated in cancer, leading to changes in adhesion and metastatic potential. Claudin-1 (Cldn1) is expressed at low levels in normal colon but is highly expressed in colorectal cancer (CRC) and promotes epithelial-mesenchymal transition and metastasis. Cancer stem cells (CSCs) are a small subset of cancer cells that display increased capacity for self-renewal and can undergo symmetric and asymmetric division to reform tumors after treatment. CSCs are resistant to cytotoxic drugs and are thought to be responsible for treatment failure, metastasis, and relapse. Significance of problem: CRC is the second leading cause of cancer-related deaths in the United States with an estimated 151,030 new cases in 2022. Although CRC has an overall relative 5-year survival rate of 64%, prognosis varies dramatically with the stage at diagnosis. Localized CRC can be treated surgically and has a 5-year survival rate of 91%, while the survival rate of metastatic CRC falls to 15%. The primary problem in treating metastatic CRC is a combination of intrinsic and acquired chemoresistance. Therefore, understanding the mechanisms of chemoresistance is vital to developing effective therapies. Hypothesis: Claudin-1 expression in colorectal cancer increases resistance to chemotherapeutic drugs and promotes cancer stem cell characteristics. Experimental design: Bioinformatic analysis was performed on a database of responders and non-responders to standard-of-care CRC chemotherapy. Cldn1 expression was manipulated in CRC cell lines, and assays were performed to evaluate chemoresistance and CSC characteristics. Results: Bioinformatic analysis of a patient dataset of responders and non-responders to chemotherapy revealed that Cldn1 expression was positively correlated with resistance to FOLFOX treatment. It was also significantly correlated with colorectal CSC marker expression including CD44, CD133, and Lgr5. Overexpression of Cldn1 in SW480 cells led to a significant increase in resistance to 5-FU, side population and ALDH-high percentage, colorectal CSC markers, and tumorigenic potential, while knockout of Cldn1 in SW620 and DLD-1 cells led to a decreased response in these assays. Follow-up experiments identified the PDZ-binding domain of Cldn1 as essential for the chemoresistant phenotype. Specifically, both CD44 and its downstream target phospho-AKT are increased with the expression of full-length but not mutated Cldn1. Conclusion: Cldn1 expression induces chemoresistance and cancer stem cell properties in colorectal cancer. Because of this, Cldn1 may serve as a biomarker in CRC for prescribing more aggressive adjuvant therapy or as a molecule for targeted treatment aimed at the resistant tumor cells responsible for treatment failure and recurrence. Citation Format: Mark Primeaux, Saiprasad Gowrikumar, Dhundy Bastola, Punita Dhawan, Amar Singh. Claudin-1 expression promotes chemoresistance and cancer stem cell characteristics in colorectal cancer [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr B021.

Berberine inhibits tumour growth in vivo and in vitro through suppressing the lincROR-Wnt/β-catenin regulatory axis in colorectal cancer.

Berberine, a non-prescription medicine clinically applied for diarrhoea and gastroenteritis. Recent studies have demonstrated that it possesses anti-tumour properties in colorectal cancer, but the exact molecular mechanism remains obscure. To elucidate the underly molecular mechanisms of berberine in colorectal cancer from a perspective of epigenetics, and tried to explore the role of lincROR-Wnt/β-catenin molecular axis in the berberine induced the anti-tumour activity in colorectal cancer. The effects of berberine on cell growth, cell cycle and apoptosis were examined in CRC cells. The in vivo effect of berberine on tumour growth was investigated using a xenograft mice model. Moreover, lincROR and Wnt/β-catenin signalling were detected by luciferase activity, qRT-PCR and western blotting assays. Berberine suppressed cell growth in vitro via inducing cell cycle arrest and apoptosis in CRC cell, and inhibited tumourigenesis in vivo. LincROR was significantly down-regulated by berberine, inducing the inactivation of the canonical Wnt/β-catenin signalling, meanwhile, the overexpression of lincROR partially reversed the suppressive effects on tumour growth and Wnt/β-catenin signalling induced by berberine. Berberine inhibits tumour growth partially via regulating the lincROR-Wnt/β-catenin regulatory axis, which provides a strategy for the design of anti-tumour drugs for CRC patients after our advanced validation.

Freeze-dried curcumin-loaded poly(lactic-co-glycolic acid) nanoparticles restrain colorectal cancer progression by targeting the notch pathway to regulate epithelial-mesenchymal transition

Despite advances in technology and treatment, colorectal cancer (CRC) remains a primary cause of cancer death worldwide, causing nearly 694,000 deaths annually with a high mortality among metastatic cases. Therefore, there is urgency to develop effective strategies to control metastasis or restrain its initiating stage and epithelial-mesenchymal transition (EMT). Activation of Notch1 is noted to positively induce cancer cell growth when inducing EMT. Curcumin is a polyphenol with anticancer activity, which works by activating various molecular pathways in cancer cells. Herein, we established curcumin-Poly (lactic-co-glycolic acid) (PLGA) nanoparticles (Cur-NPs) and investigated their physicochemical properties in CRC to provide a novel insight into treatment of CRC. Cur-NPs were established by emulsion solvent evaporation. CRC cells (HCT116, HT29) were co-cultured with 0, 1, 2.5, 5, and 10 μM Cur-NPs, respectively. After treatment, clone formation assay determined CRC cell viability, migration and invasion, whilst Terminal deoxynucleotidyl transferase mediated dUTP Nick End Labeling (TUNEL) assessed cell apoptosis. Besides, EMT markers levels in each group were detected to evaluate the impact of Cur-NPs on the EMT process. The transmission electron microscopy (TEM) pictures depicted classical features of Cur-NPs, with encapsulation efficiency of Cur-NPs 70.685±2.597%, and drug loading rate of 2.831±0.108%. The CRC cells absorbed the Cur-NPs within 30 min, and the absorption was as early as 10 min, while fluorescence reached climax at 30 min. The advent of Cur-NPs at different concentration greatly suppressed CRC cell viability and hindered their clone formation in HCT116 and HT29 cells, but elevated apoptotic rate of cancer cells with concentration of Cur-NPs proportional to the rate, while the apoptosis of normal colorectal epithelial cells was not affected. 10 μM Cur-NPs group had the highest apoptosis rate and poorest invasion and migration ability. Moreover, upon treatment with Cur-NPs, E-cadherin expression increased, but the proteins in the Notch pathway declined dramatically. Cur-NPs suppressed CRC cell progression through regulating the Notch signaling pathway and decelerating the EMT process of CRC cells.

P74-8 Rice bran consumption in high-risk populations to prevent colorectal cancer: A systematic review

Colorectal cancer (CRC) is still one of the most common cancers in the world, with diet being one of the major risk factors. Rice Bran (RB) possesses chemoprevention properties in CRC by promoting intestinal health through several mechanisms. The immense potential of RB to be included in cancer preventive measures remains to be uncovered. This systematic review aims to find associations between RB consumption and the prevention of colorectal cancer in high-risk populations.

Abstract 1409: Synergistic antitumorigenic activity of Berberine and oligomeric proanthocyanidins through regulation of PI3-AKt signaling pathway in colorectal cancer

Abstract Background: The development of chemo-resistance against conventional chemotherapeutic drugs presents a major clinical challenge in the management of patients with colorectal cancer (CRC). Accumulating body of data in recent years have shown that active principles within various naturally-occurring dietary botanicals not only offer time-tested safety and anti-cancer efficacy, but a combination of certain compounds can overcome the elusive chemotherapeutic resistance in cancer patients. In this regard, data in recent years have shown that berberine (BBR) and oligomeric proanthocyanidins (OPCs) from the grape-seed extract have significant anti-tumorigenic properties in CRC, and a more recent study reported existence of synergism between these two natural medicines in patients with type 2 diabetes. Accordingly, herein we hypothesized that BBR and OPCs might regulate synergistically multiple oncogenic pathways to exert a superior anti-cancer activity in CRC. Methods: We performed a series of experiment in various cell lines, followed by their interrogation in patient-derived organoids (PDOs) to evaluate the synergistic anti-tumorigenic effects of BBR and OPCs in CRC cells. In addition, using genome-wide RNA sequencing analyses, we identified specific functional determinants and key targeted genes and pathways regulated by the combined therapeutic approach with these compounds. Results: To confirm our hypothesis, we first evaluated the potential of OPCs to increase the cellular uptake of BBR in CRC cells, by measuring the fluorescent signal of BBR in multiple cell lines treated individually or their combination. The synergistic anti-tumorigenic effects of BBR and OPCs were observed in various functional assays including reduced cell viability, colony formation potential, wound healing, and invasion assays. Furthermore, the combined treatment with these compounds potentiated the cell apoptosis in an Annexin V binding assay. It was intriguing to note that we were able to successfully validate all cell culture findings in the PDO models from multiple CRC patients. Whole genome transcriptomic profiling identified oncogene MYB, including in PI3-AKT signaling pathway as one of the key pathways that was critically involved in mediating the anti-tumorigenic properties of this combined therapy. Conclusions: We for the first time demonstrate that a combined treatment with BBR and OPCs synergistically promotes the anti-tumorigenic properties in CRC. This synergism was potentially due to enhanced apoptosis and the regulation of oncogenic MYB in the PI3-Akt signaling pathway; hence, offering an attractive potential for the use of these two compounds as adjuvant treatment options in patients with CRC. Citation Format: Keisuke Okuno, Rachana Garg, Masanori Tokunaga, Yusuke Kinugasa, Ajay Goel. Synergistic antitumorigenic activity of Berberine and oligomeric proanthocyanidins through regulation of PI3-AKt signaling pathway in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1409.

Berberine and Oligomeric Proanthocyanidins Exhibit Synergistic Efficacy Through Regulation of PI3K-Akt Signaling Pathway in Colorectal Cancer.

BackgroundNaturally occurring dietary botanicals offer time-tested safety and anti-cancer efficacy, and a combination of certain compounds has shown to overcome the elusive chemotherapeutic resistance, which is of great significance for improving the mortality of patients with colorectal cancer (CRC). Accordingly, herein, we hypothesized that berberine (BBR) and oligomeric proanthocyanidins (OPCs) might regulate synergistically multiple oncogenic pathways to exert a superior anti-cancer activity in CRC.MethodsWe performed a series of cell culture studies, followed by their interrogation in patient-derived organoids to evaluate the synergistic effect of BBR and OPCs against CRC. In addition, by performing whole genome transcriptomic profiling we identified the key targeted genes and pathways regulated by the combined treatment.ResultsWe first demonstrated that OPCs facilitated enhanced cellular uptake of BBR in CRC cells by measuring the fluorescent signal of BBR in cells treated individually or their combination. The synergism between BBR and OPCs were investigated in terms of their anti-tumorigenic effect on cell viability, clonogenicity, migration, and invasion. Furthermore, the combination treatment potentiated the cellular apoptosis in an Annexin V binding assay. Transcriptomic profiling identified oncogene MYB in PI3K-AKT signaling pathway might be critically involved in the anti-tumorigenic properties of the combined treatment. Finally, we successfully validated these findings in patient-derived CRC tumor organoids.ConclusionsCollectively, we for the first time demonstrate that a combined treatment of BBR and OPCs synergistically promote the anti-tumorigenic properties in CRC possibly through the regulation of cellular apoptosis and oncogene MYB in the PI3K-Akt signaling pathway.

Biochemical and Metabolical Pathways Associated with Microbiota-Derived Butyrate in Colorectal Cancer and Omega-3 Fatty Acids Implications: A Narrative Review.

Knowledge regarding the influence of the microbial community in cancer promotion or protection has expanded even more through the study of bacterial metabolic products and how they can modulate cancer risk, which represents an extremely challenging approach for the relationship between intestinal microbiota and colorectal cancer (CRC). This review discusses research progress on the effect of bacterial dysbiosis from a metabolic point of view, particularly on the biochemical mechanisms of butyrate, one of the main short chain fatty acids (SCFAs) with anti-inflammatory and anti-tumor properties in CRC. Increased daily intake of omega-3 polyunsaturated fatty acids (PUFAs) significantly increases the density of bacteria that are known to produce butyrate. Omega-3 PUFAs have been proposed as a treatment to prevent gut microbiota dysregulation and lower the risk or progression of CRC.

Regulation of ZO-1 on β-catenin mediates sulforaphane suppressed colorectal cancer stem cell properties in colorectal cancer.

Cancer stem cells (CSCs) function as the driving force of cancer initiation and progression. Wnt/β-catenin is the core pluripotency pathway in CSCs, while its crucial regulator has not been fully elucidated yet. Here, we evaluated the role of ZO-1, a component of the tight junction protein complex, in colorectal CSCs, and found ZO-1 downregulation in both colorectal cancer cells and spheres. Over-expression of ZO-1 can inhibit the sphere-forming capacity and CSC marker expression in spheres. Immunofluorescence staining and co-immunoprecipitation analysis further revealed the interaction between ZO-1 and β-catenin and the repressed role of ZO-1 in β-catenin nuclear accumulation. Using in vitro and in vivo models, we suggested the suppression effects of sulforaphane on CSCs via the ZO-1/β-catenin axis in colorectal cancer. The findings from this study depicted for the first time that ZO-1 dampened colorectal CSCs by interacting with β-catenin and attenuated its nuclear translocation, providing new insights into the mechanisms and applications of sulforaphane in targeting CSCs.

HOTAIR regulates colorectal cancer stem cell properties and promotes tumorigenicity by sponging miR-211-5p and modulating FLT-1

ABSTRACT We intended to investigate the underlying mechanism of action of long noncoding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR) in colorectal cancer (CRC) progression, especially in tumor cell stemness. For that purpose, different assays were performed such as real-time PCR and western blotting to determine the expression of target genes. Cell stemness was determined by sphere formation assay, flow cytometry assay, and the analysis of stemness‐related markers. The interplay among target genes was evaluated using bioinformatics analyses, luciferase reporter and biotin-labeled RNA pull down assays. We found that HOTAIR was highly expressed and predicted poor prognosis survival in CRC. Downregulation of HOTAIR repressed tumor malignant behaviors and cancer stemness. Mechanistically, HOTAIR facilitated the expression of the microRNA (miR)-211-5p target gene fms-like tyrosine kinase-1 (FLT-1), thereby modulating cancer stem cell (CSC) properties in CRC. We conclude that HOTAIR/miR-211-5p/FLT-1 axis contributes to CRC cancer stemness.

KRAS phosphorylation regulates cell polarization and tumorigenic properties in colorectal cancer.

Oncogenic mutations of KRAS are found in the most aggressive human tumors, including colorectal cancer. It has been suggested that oncogenic KRAS phosphorylation at Ser181 modulates its activity and favors cell transformation. Using nonphosphorylatable (S181A), phosphomimetic (S181D), and phospho-/dephosphorylatable (S181) oncogenic KRAS mutants, we analyzed the role of this phosphorylation to the maintenance of tumorigenic properties of colorectal cancer cells. Our data show that the presence of phospho-/dephosphorylatable oncogenic KRAS is required for preserving the epithelial organization of colorectal cancer cells in 3D cultures, and for supporting subcutaneous tumor growth in mice. Interestingly, gene expression differed according to the phosphorylation status of KRAS. In DLD-1 cells, CTNNA1 was only expressed in phospho-/dephosphorylatable oncogenic KRAS-expressing cells, correlating with cell polarization. Moreover, lack of oncogenic KRAS phosphorylation leads to changes in expression of genes related to cell invasion, such as SERPINE1, PRSS1,2,3, and NEO1, and expression of phosphomimetic oncogenic KRAS resulted in diminished expression of genes involved in enterocyte differentiation, such as HNF4G. Finally, the analysis, in a public data set of human colorectal cancer, of the gene expression signatures associated with phosphomimetic and nonphosphorylatable oncogenic KRAS suggests that this post-translational modification regulates tumor progression in patients.

Claudin-7 deficiency promotes stemness properties in colorectal cancer through Sox9-mediated Wnt/\u03b2-catenin signalling

BackgroundColorectal cancer (CRC) is a common malignant tumour of the digestive tract that is characterized by high patient morbidity and mortality rates. Claudin-7 (Cldn7), a tight junction protein, was recently reported to function as a candidate tumour suppressor gene in CRC. Our previous study demonstrated that the large intestine of C57/BL6 mice showed intestinal adenomas and abnormal Ki67 expression and distribution in the intestinal crypt when Cldn7 was knocked out. The aim of this study was to further investigate whether Cldn7 deficiency has non-tight junction functions, affects intestinal stemness properties, promotes CRC and to determine the specific mechanism.MethodsCell proliferation assays, migration assays, apoptosis assays, tumour sphere formation assays in vitro, and subcutaneous xenograft models in vivo were used to determine the effects of Cldn7 knockdown on the biological characteristics of CRC stem cells. Western blotting, qPCR and immunofluorescence staining were performed to identify the epithelial-mesenchymal transition and the activation of Wnt/β-catenin pathway in CRC stem cells. Cldn7 inducible conditional gene knockout mice and immunohistochemical staining further verified this hypothesis in vivo. The mechanism and target of Cldn7 were determined by performing a chromatin immunoprecipitation (ChIP) assay and coimmunoprecipitation (CoIP) assay.ResultsCldn7 knock down in CRC stem cells promoted cell proliferation, migration, and globular growth in serum-free medium and the ability to form xenograft tumours; cell apoptosis was inhibited, while the cellular epithelial-mesenchymal transition was also observed. These changes in cell characteristics were achieved by activating the Wnt/β-catenin pathway and promoting the expression of downstream target genes after β-catenin entry into the nucleus, as observed in CRC cell lines and Cldn7 gene knockout mouse experiments. Using ChIP and CoIP experiments, we initially found that Cldn7 and Sox9 interacted at the protein level to activate the Wnt/β-catenin pathway.ConclusionsBased on our research, Cldn7 deficiency confers stemness properties in CRC through Sox9-mediated Wnt/β-catenin signalling. This result clarifies that Cldn7 plays an inhibitory role in CRC and reveals a possible molecular mechanism, which is conducive to further research on Cldn7 and cancer stem cells.