Agent For Colorectal Cancer Research Articles

The Anticancer Poperties of Diosgenin on Colorectal Cancer Cells Induced by Wnt/Β Catenin Signaling Pathway

Background: Colorectal cancer (CC) is one of the most prevalent cancers globally. Due to the severe side effects and the development of drug resistance in CC treatments, current therapeutic strategies often prove ineffective. As a result, there is a growing interest in exploring traditional medicinal plants as alternative treatment options for various human diseases. Diosgenin, a bioactive compound derived from plants, has shown potential in inhibiting the growth of human CC cells. The Wnt/β-catenin signaling pathway plays a critical role in colorectal tumorigenesis. Objectives: This study investigates the effects of Diosgenin on the Wnt/β-catenin pathway in CC cells. Methods: Colorectal cancer cells were treated with Diosgenin, and cell viability and plasma membrane integrity were assessed using the MTT assay and lactate dehydrogenase (LDH) activity assay, respectively. Apoptosis was evaluated through Annexin V/PI staining. The expression of Wnt/β-catenin-related genes was analyzed by quantitative PCR (qPCR). Results: Diosgenin significantly inhibited CC cell viability in a time- and concentration-dependent manner after 24, 48, 72, and 96 hours of exposure (P < 0.05). The IC50 values were determined to be 203.55, 122.95, 70.11, and 7.34 µM at 24, 48, 72, and 96 hours, respectively. Diosgenin at its IC50 concentration induced a significant increase in cell apoptosis after 24 hours of treatment (P < 0.05). Additionally, it caused a significant reduction in the expression of β-catenin, cyclin D1, and Pin1 (βCP). Conclusions: Diosgenin exhibits anti-CC effects by inhibiting the expression of βCP genes involved in the Wnt/β-catenin pathway, suggesting its potential as a therapeutic agent for CC.

The dynamic changes of circulating myeloid-derived suppressor cells (MDSCs) subsets in patients with colorectal cancer undergoing oxaliplatin-based chemotherapy.

62 Background: Increased level of circulating myeloid-derived suppressor cells (MDSCs) have been associated with higher tumor stage, poorer survival, and poorer response to therapeutic agents in colorectal cancer (CRC). It has been reported that the common first-line chemotherapy involving combination with oxaliplatin mediated MDSCs depletion via induction of cell death. However, this phenomenon is yet to be further investigated since it only occurred in polymophonuclear MDSC (PMN-MDSC) subset, not in monocytic MDSC (M-MDSC). The present study aims to learn deeper on the dynamic changes of circulating MDSCs in response to oxaliplatin-based treatment in CRC patients. Methods: This was a prospective study that recruited 30 treatment-naïve patients with varying stage of CRC who were scheduled to receive oxaliplatin-based chemotherapy. Blood sampling was conducted prior and at several time points during and after chemotherapy. Multicolor flow cytometry assay was used to analyze the proportion of HLA-DR-, CD33+, and CD15+ (PMN-MDSC) and CD14+ (M-MDSC) cells within peripheral blood mononuclear cells (PBMCs). Other essential tumor biomarkers such as carcinoembryonic antigen (CEA) and tumor infiltrating lymphocytes (TILs) were assessed as well. As control, 14 healthy subjects were recruited. Results: Our result showed that circulating PMN-MDSCs was significantly higher in CRC patients compared to healthy subjects (p=0.003), whilst insignificant result was shown by M-MDSCs (p=0.890). Following chemotherapy, MDSCs level showed dynamic changes. Interestingly, a subgroup of CRC patients with decreased in both PMN- and M-MDSCs levels on D-14 chemotherapy were consistently showed a significant decreased of MDSCs level during and after therapy completion compared to baseline (p=0.0078). Conclusions: Circulating MDSCs level, particularly PMN-MDSCs in CRC patients was significantly higher compared to healthy subjects. Changes in both circulating PMN- and M-MDSCs levels at D-14 chemotherapy might have prognostic value in oxaliplatin-based chemotherapy.

Terpenoids from quinoa reverse drug resistance of colon cancer by upregulating miR-495-3p.

Quinoa contains far more nutrients than any traditional grain crop. It is known that terpenoids in quinoa have anti-inflammatory and antitumor effects, but their role in reversing drug resistance remains unclear. Our previous studies showed that quinoa-derived terpenoid compounds (QBT) can inhibit the occurrence and development of colon cancer. This study further indicates that QBT markedly reverse drug resistance of colon cancer. The results showed that QBT combined with 5-fluorouracil (5-Fu) treatment significantly enhanced the chemotherapy sensitivity of HCT-8/Fu, compared with 5-Fu treatment alone. Moreover, we found that QBT significantly reduced the expression of drug-resistant proteins (P-gp, MRP1, BCRP), and increased the accumulation of chemotherapy drugs. Taking P-gp as the target for biogenesis prediction analysis, results showed that upregulation of miR-495-3p enhanced the chemosensitivity of drug-resistant HCT-8/Fu cells. Besides, the results showed that miR-495-3p was abnormally methylated in HCT-8/Fu compared with HCT-8 colon cancer cells. The expression of methyltransferases DNMT1, DNMT3a and DNMT3b was abnormal. After QBT treatment, the expression level of methyltransferases returned to normal. In addition, the QBT + 5Fu group showed inhibition of tumors in nude mice. QBT treatment downregulated the expression of drug-resistant protein P-gp by inhibiting the methylation of miR-495-3p, and enhanced the accumulation of 5-Fu in vivo, which in turn reversed its chemoresistance. This suggests that QBT has potential ability as a new drug-resistance reversal agent in colorectal cancer. © 2024 Society of Chemical Industry.

Pharmacokinetic studies, molecular docking, and molecular dynamics simulations of phytochemicals from Morus alba: a multi receptor approach for potential therapeutic agents in colorectal cancer.

This study explores the therapeutic potential of phytochemicals derived from Morus alba for colorectal cancer (CRC) treatment. Colorectal cancer is a global health concern with increasing mortality rates, necessitating innovative strategies for prevention and therapy. Employing in silico analysis, molecular docking techniques (MDT), and molecular dynamics simulations (MDS), the study investigates the interactions between Morus alba-derived phytochemicals and key proteins (AKT1, Src, STAT3, EGFR) implicated in CRC progression. ADME/T analysis screens 78 phytochemicals for drug-like and pharmacokinetic properties. The study integrates Lipinski's Rule of Five and comprehensive bioactivity assessments, providing a nuanced understanding of Morus alba phytoconstituent's potential as CRC therapeutic agents. Notably, 14 phytochemicals out of 78 emerge as potential candidates, demonstrating oral bioavailability and favorable bioactivity scores. Autodock 1.5.7 is employed for energy minimization followed by molecular docking with the highest binding energy observed to be -11.7kcal/mol exhibited by Kuwanon A against AKT1. Molecular dynamics simulations and trajectory path analysis were conducted between Kuwanon A and AKT1 at the Pleckstrin homology (PH) domain region (TRP80), revealing minimal deviations. In comparison to the standard drug Capivasertib, the phytochemical Kuwanon A emerges as a standout candidate based on computational analysis. This suggests its potential as an alternative to mitigate the limitations associated with the standard drug. The research aims to provide insights for future experimental validations and to stimulate the development of Kuwanon A as a novel, effective therapeutic agent for managing colorectal cancer.

Curcumin and its anti-colorectal cancer potential: From mechanisms of action to autophagy.

Colorectal cancer (CRC) development and progression, one of the most common cancers globally, is supported by specific mechanisms to escape cell death despite chemotherapy, including cellular autophagy. Autophagy is an evolutionarily highly conserved degradation pathway involved in a variety of cellular processes, such as the maintenance of cellular homeostasis and clearance of foreign bodies, and its imbalance is associated with many diseases. However, the role of autophagy in CRC progression remains controversial, as it has a dual function, affecting either cell death or survival, and is associated with cellular senescence in tumor therapy. Indeed, numerous data have been presented that autophagy in cancers serves as an alternative to cell apoptosis when the latter is ineffective or in apoptosis-resistant cells, which is why it is also referred to as programmed cell death type II. Curcumin, one of the active constituents of Curcuma longa, has great potential to combat CRC by influencing various cellular signaling pathways and epigenetic regulation in a safe and cost-effective approach. This review discusses the efficacy of curcumin against CRC in vitro and in vivo, particularly its modulation of autophagy and apoptosis in various cellular pathways. While clinical studies have assessed the potential of curcumin in cancer prevention and treatment, none have specifically examined its role in autophagy. Nonetheless, we offer an overview of potential correlations to support the use of this polyphenol as a prophylactic or co-therapeutic agent in CRC.

Potential and toxicity effects of fish omega-3 fatty acid as a chemopreventive agent in colorectal cancer: A scoping review

Colorectal cancer (CRC), a malignancy that affects the colon and rectum, is influenced by gene mutations, epigenetic changes, local inflammation, and lifestyle risk factors. New cases of CRC globally account for 10%, with mortality at 9.4%, while Indonesia occupies the top four incidence and mortality cases. A family history of CRC requires preventive measures, including consuming functional foods to maintain the colon microenvironment. This article aims to review the potency and toxicity effects of omega-3 fish fatty acids as a chemopreventive agent against CRC. The data sources were original articles about omega-3 fish fatty acids as CRC chemopreventive agents, published in 2012-2022 and in English or Indonesian. Databases used are Ovid, ScienceDirect, ProQuest, PubMed, Springer Link, EBSCO, and Google Scholar using Boolean search. The selection of studies followed the PRISMA-ScR method. Of the nine articles selected, fish omega-3 fatty acids had the potential as a chemopreventive agent against CRC, with several variations in daily dose ranges accompanied by a good lifestyle. Oral omega-3 fish supplementation gave benefits in the range of 96 mg–2,000 mg of eicosapentaenoic acid (EPA) and between 360 mg–1,000 mg of docosahexaenoic acid (DHA), with a daily intake varying between 0–14 grams/day. One study reported a toxic effect of fish omega-3 fatty acids, which raised the risk of post-operative infection after parenteral (intravenous) administration. There are no reported side effects across eight studies following oral preparation administration. The omega-3 fish fatty acid shows potential as a chemopreventive therapy for CRC; further studies are required to explore the parenteral administration-associated toxic effects.

Novel insights into the role of translesion synthesis polymerase in DNA incorporation and bypass of 5-fluorouracil in colorectal cancer.

5-Fluorouracil (5-FU) is the first-line chemotherapeutic agent in colorectal cancer, and resistance to 5-FU easily emerges. One of the mechanisms of drug action and resistance of 5-FU is through DNA incorporation. Our quantitative reverse-transcription PCR data showed that one of the translesion synthesis (TLS) DNA polymerases, DNA polymerase η (polη), was upregulated within 72 h upon 5-FU administration at 1 and 10 μM, indicating that polη is one of the first responding polymerases, and the only TLS polymerase, upon the 5-FU treatment to incorporate 5-FU into DNA. Our kinetic studies revealed that 5-fluoro-2'-deoxyuridine triphosphate (5FdUTP) was incorporated across dA 41 and 28 times more efficiently than across dG and across inosine, respectively, by polη indicating that the mutagenicity of 5-FU incorporation is higher in the presence of inosine and that DNA lesions could lead to more mutagenic incorporation of 5-FU. Our polη crystal structures complexed with DNA and 5FdUTP revealed that dA:5FdUTP base pair is like dA:dTTP in the active site of polη, while 5FdUTP adopted 4-enol tautomer in the base pairs with dG and HX increasing the insertion efficiency compared to dG:dTTP for the incorrect insertions. These studies confirm that polη engages in the DNA incorporation and bypass of 5-FU.

Morindone as a potential therapeutic compound targeting TP53 and KRAS mutations in colorectal cancer cells

There is an increasing demand for anticancer agent in treating colorectal cancer (CRC) with frequently mutated TP53 and KRAS genes. Phytochemical compounds are suitable as chemoprevention for CRC since dietary factor is a major risk factor. Anthraquinones from Morinda citrifolia L. were previously reported with various pharmacological properties. Various in vitro experiments were conducted to investigate the effects of two anthraquinones: damnacanthal and morindone on the cell proliferation, cell cycle, apoptosis, gene expression and protein expression in two CRC cells: HCT116 and HT29. Real-time monitoring of CRC cells showed that both anthraquinones exerted significant anti-proliferative effects in a dose- and time-dependent manner. Next, cell cycle analysis revealed an increase in the percentage of CRC cells in the G1 phase under anthraquinones treatment. Fluorescence microscopy also showed an increment of apoptotic cells under anthraquinones’ treatment. siRNA transfection was conducted to evaluate the mediating effect of gene knockdown on mutated TP53 and KRAS in CRC cells. Before transfection, qRT-PCR analysis showed that only morindone downregulated the gene expression of mutated TP53 and KRAS and then further downregulated them after transfection. Both damnacanthal and morindone treatments further downregulated the expression of these two genes but upregulated at the protein expression level. Furthermore, gene knockdown also sensitised CRC cells to both damnacanthal and morindone treatments, resulting in lowered IC50 values. The accumulation of cells at the G1 phase was reduced after gene knockdown but increased after damnacanthal and morindone treatments. In addition, gene knockdown has increased the number of apoptotic cells in both cell lines and further increment was observed after anthraquinone treatment. In conclusion, morindone could be a competitive therapeutic agent in CRC by exhibiting multiple mechanism of anti-cancer actions.

Oral administration of Manuka honey induces IFNγ-dependent resistance to tumor growth that correlates with beneficial modulation of gut microbiota composition.

To investigate the potential of Manuka honey (MH) as an immunomodulatory agent in colorectal cancer (CRC) and dissect the underlying molecular and cellular mechanisms. MH was administered orally over a 4 week-period. The effect of MH treatment on microbiota composition was studied using 16S rRNA sequencing of fecal pellets collected before and after treatment. Pretreated mice were implanted with CRC cells and followed for tumor growth. Tumors and lymphoid organs were analyzed by flow cytometry (FACS), immunohistochemistry and qRT-PCR. Efficacy of MH was also assessed in a therapeutic setting, with oral treatment initiated after tumor implantation. We utilized IFNγ-deficient mice to determine the importance of interferon signaling in MH-induced immunomodulation. Pretreatment with MH enhanced anti-tumor responses leading to suppression of tumor growth. Evidence for enhanced tumor immunogenicity included upregulated MHC class-II on intratumoral macrophages, enhanced MHC class-I expression on tumor cells and increased infiltration of effector T cells into the tumor microenvironment. Importantly, oral MH was also effective in retarding tumor growth when given therapeutically. Transcriptomic analysis of tumor tissue highlighted changes in the expression of various chemokines and inflammatory cytokines that drive the observed changes in tumor immunogenicity. The immunomodulatory capacity of MH was abrogated in IFNγ-deficient mice. Finally, bacterial 16S rRNA sequencing demonstrated that oral MH treatment induced unique changes in gut microbiota that may well underlie the IFN-dependent enhancement in tumor immunogenicity. Our findings highlight the immunostimulatory properties of MH and demonstrate its potential utilization in cancer prevention and treatment.

Abstract B005: Tolerance to colibactin correlates with response to chemotherapeutic agents in colorectal cancer

Abstract Introduction. The bacterial genotoxin colibactin is enriched in colorectal cancer (CRC) and promotes the accumulation of mutations that drive tumorigenesis. However, systematic assessment of its impact on DNA damage response is lacking and the effect of colibactin exposure on response to other genotoxic agents (such as chemotherapy) is missing. Materials and methods: We implemented an in vitro bacteria-coculture system to assess the effect of colibactin on a representative subset of 40 molecularly and pharmacologically annotated CRC cell lines and in a panel of isogenic DDR KO cell lines we generated. We further validated our results in patient-derived organoids. Finally, we recapitulated prolonged exposure to colibactin occurring during tumorigenesis by chronically infecting sensitive cells until the emergence of a tolerant phenotype. Results: We found that different cell lines display specific sensitivity to colibactin’s genotoxic stress: while colibactin-tolerant cells are capable of quickly and efficiently repairing colibactin-induced DNA damage, sensitive cells lack this ability. Moreover, we found that homologous recombination (HR) proficiency discriminates colibactin-tolerant cells, which display higher levels of RAD51 foci (as marker of activation of HR) compared to sensitive cells upon infection with colibactin. Screening of isogenic DDR KO cell lines revealed that genetic inactivation of the intertwined pathways of HR (through KO of ATM) and replication stress (RS) response (through KO of ATRIP) significantly sensitized cells to colibactin. In addition, we found that restoration of HR activity was sufficient to induce a colibactin-tolerant phenotype in initially sensitive cell lines. Notably, thanks to a previous effort of pharmacological characterization of CRC cell lines in our lab, we found a significant correlation between sensitivity to colibactin and irinotecan active metabolite SN38, but not oxaliplatin. We validated the same correlation in patient-derived organoids annotated for response to SN38. While colibactin, SN38 and oxaliplatin all induced RS in treated cells, we found that colibactin and SN38 showed a similar DNA damage response which involved activation of ATM. Finally, chronic re-infection of sensitive, HR-deficient CRC cells with colibactin selected a tolerant phenotype characterized by restoration of HR activity. Of translational relevance, colibactin-tolerant derivative cells acquired cross-resistance to SN38 and PARP inhibitor olaparib but not to oxaliplatin. Conclusion: Our results shed novel insight into colibactin’s genotoxic mechanism and support a model in which colibactin both promotes tumorigenesis and acts as an evolutionary bottleneck which selects HR proficient CRC cells. Furthermore, our study provides preclinical evidence on colibactin’s role in promoting chemoresistance in colorectal cancer. Citation Format: Alberto Sogari, Emanuele Rovera, Nicole Megan Reilly, Simona Lamba, Erika Durinikova, Annalisa Lorenzato, Marco Avolio, Eleonora Piumatti, Mariangela Russo, Sabrina Arena, Livio Trusolino, Manuela Donalisio, Federica Di Nicolantonio, David Lembo, Alberto Bardelli. Tolerance to colibactin correlates with response to chemotherapeutic agents in colorectal cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: DNA Damage Repair: From Basic Science to Future Clinical Application; 2024 Jan 9-11; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2024;84(1 Suppl):Abstract nr B005.

A novel CPT1A covalent inhibitor modulates fatty acid oxidation and CPT1A-VDAC1 axis with therapeutic potential for colorectal cancer

Colorectal cancer (CRC) is a common and deadly disease of the digestive system, but its targeted therapy is hampered by the lack of reliable and specific biomarkers. Hence, discovering new therapeutic targets and agents for CRC is an urgent and challenging task. Here we report that carnitine palmitoyltransferase 1A (CPT1A), a mitochondrial enzyme that catalyzes fatty acid oxidation (FAO), is a potential target for CRC treatment. We show that CPT1A is overexpressed in CRC cells and that its inhibition by a secolignan-type compound, 2,6-dihydroxypeperomin B (DHP-B), isolated from the plant Peperomia dindygulensis, suppresses tumor cell growth and induces apoptosis. We demonstrate that DHP-B covalently binds to Cys96 of CPT1A, blocks FAO, and disrupts the mitochondrial CPT1A-VDAC1 interaction, leading to increased mitochondrial permeability and reduced oxygen consumption and energy metabolism in CRC cells. We also reveal that CPT1A expression correlates with the survival of tumor-bearing animals and that DHP-B exhibits anti-CRC activity in vitro and in vivo. Our study uncovers the molecular mechanism of DHP-B as a novel CPT1A inhibitor and provides a rationale for its preclinical development as well as a new strategy for CRC targeted therapy.

Oils from Transgenic Flax Lines as Potential Chemopreventive Agents in Colorectal Cancer.

Colorectal cancer is a major global health concern, and the need for effective chemopreventive agents is paramount. This study aimed to evaluate the potential of oils from transgenically modified flax for the prevention of colorectal cancer, in relation to the oil concertation. Flaxseed oils were obtained from traditional (Nike) and genetically modified flax lines (M and B). Cell viability assays were performed on various cancer cell lines, including colon adenocarcinoma cells. Flaxseed oil B exhibited the strongest anti-proliferative properties compared to the reference drugs and other oils. Additionally, M and B oils showed enhanced accumulation of Rhodamine 123 and increased apoptosis in colorectal cancer cells. M oil exhibited the highest levels of p53 protein. Notably, the tested transgenic oils did not induce metastasis and displayed stronger inhibition of COX-1 compared to COX-2. These data indicate the utility of flaxseed oils, especially from the M line, as adjuvants in colorectal cancer treatment, targeting the colon specifically.

Abdominal Ultrasonography After Transrectal Filling With Contrast Agents in Colorectal Cancer With Severely Stenotic Lesions

Abdominal ultrasonography after transrectal filling with contrast agent (AU-TFCA) was retrospectively evaluated with respect to determination of T stage and lesion length in patients with colorectal cancer (CRC) who had previously failed colonoscopy because of severe intestinal stenosis. The population comprised 83 patients with CRC with intestinal stenosis and previously failed colonoscopy who underwent AU-TFCA, and in addition contrast-enhanced computed tomography (CECT) and/or magnetic resonance imaging (MRI), 2 wk before surgery. The diagnostic performance of AU-TFCA and CECT/MRI was evaluated relative to the post-operative pathological results (PPRs) by paired sample t-test, receiver operator characteristic (ROC) curve, Pearson's χ2-test and κ and intraclass correlation coefficients. The T staging identified via AU-TFCA, but not CECT/MRI, was relatively consistent with that of the PPRs (linearly weighted κ coefficient: 0.558, p < 0.001, and linearly weighted κ coefficient: 0.237, p < 0.001, respectively). The overall diagnostic accuracy of T staging based on AU-TFCA (83.1%) was significantly higher than that based on CECT/MRI (50.6%). Regarding lesion length, the results of AU-TFCA and PPRs were comparable (t=1.852, p=0.068), but those of CECT/MRI and PPRs were significantly different (t=8.450, p < 0.001). AU-TFCA is effective in evaluation of lesion length and T stage in patients with severely stenotic CRC lesions who previously failed colonoscopy. The diagnostic accuracy of AU-TFCA is significantly better compared with that of CECT/MRI.

Translational relevance of SOS1 targeting for KRAS-mutant colorectal cancer.

It has been challenging to target mutant KRAS (mKRAS) in colorectal cancer (CRC) and other malignancies. Recent efforts have focused on developing inhibitors blocking molecules essential for KRAS activity. In this regard, SOS1 inhibition has arisen as an attractive approach for mKRAS CRC given its essential role as a guanine nucleotide exchange factor for this GTPase. Here, we demonstrated the translational value of SOS1 blockade in mKRAS CRC. We used CRC patient-derived organoids (PDOs) as preclinical models to evaluate their sensitivity to SOS1 inhibitor BI3406. A combination of in silico analyses and wet lab techniques was utilized to define potential predictive markers for SOS1 sensitivity and potential mechanisms of resistance in CRC. RNA-seq analysis of CRC PDOs revealed two groups of CRC PDOs with differential sensitivities to SOS1 inhibitor BI3406. The resistant group was enriched in gene sets involving cholesterol homeostasis, epithelial-mesenchymal transition, and TNF-α/NFκB signaling. Expression analysis identified a significant correlation between SOS1 and SOS2 mRNA levels (Spearman's ρ 0.56, p < 0.001). SOS1/2 protein expression was universally present with heterogeneous patterns in CRC cells but only minimal to none in surrounding nonmalignant cells. Only SOS1 protein expression was associated with worse survival in patients with RAS/RAF mutant CRC (p = 0.04). We also found that SOS1/SOS2 protein expression ratio >1 by immunohistochemistry (p = 0.03) instead of KRAS mutation (p = 1) was a better predictive marker to BI3406 sensitivity of CRC PDOs, concordant with the significant positive correlation between SOS1/SOS2 protein expression ratio and SOS1 dependency. Finally, we showed that GTP-bound RAS level underwent rebound even in BI3406-sensitive PDOs with no change of KRAS downstream effector genes, thus suggesting upregulation of guanine nucleotide exchange factor as potential cellular adaptation mechanisms to SOS1 inhibition. Taken together, our results show that high SOS1/SOS2 protein expression ratio predicts sensitivity to SOS1 inhibition and support further clinical development of SOS1-targeting agents in CRC.

Abstract 5900: Tolerance to colibactin correlates with response to chemotherapeutic agents in colorectal cancer

Abstract Introduction: The bacterial genotoxin colibactin is enriched in colorectal cancer (CRC) and promotes the accumulation of mutations that drive tumorigenesis. However, systematic assessment of its impact on DNA damage response is lacking and the effect of colibactin exposure on response to other genotoxic agents (such as chemotherapy) is missing. Materials and Methods: We implemented an in vitro bacteria-coculture system to assess the effect of colibactin on a representative subset of 40 molecularly and pharmacologically annotated CRC cell lines and in a panel of isogenic DDR KO cell lines we generated. We further validated our results in patient-derived organoids. Finally, we recapitulated prolonged exposure to colibactin occurring during tumorigenesis by chronically infecting sensitive cells until the emergence of a tolerant phenotype.} Results: We found that different cell lines display specific sensitivity to colibactin’s genotoxic stress: while colibactin-tolerant cells are capable to quickly and efficiently repair colibactin-induced DNA damage, sensitive cells lack this ability. Moreover, we found that homologous recombination (HR) proficiency discriminates colibactin-tolerant cells, which display higher levels of RAD51 foci (as marker of activation of HR) compared to sensitive cells upon infection with colibactin. Screening of isogenic DDR KO cell lines revealed that genetic inactivation of the intertwined pathways of HR (through KO of ATM) and replication stress (RS) response (through KO of ATRIP) significantly sensitized cells to colibactin. In addition, we found that restoration of HR activity was sufficient to induce a colibactin-tolerant phenotype in initially sensitive cell lines. Notably, thanks to a previous effort of pharmacological characterization of CRC cell lines in our lab, we found a significant correlation between sensitivity to colibactin and irinotecan active metabolite SN38, but not oxaliplatin. We validated the same correlation in patient-derived organoids annotated for response to SN38. While colibactin, SN38 and oxaliplatin all induced RS in treated cells, we found that colibactin and SN38 showed a similar DNA damage response which involved activation of ATM. Finally, chronic re-infection of sensitive, HR-deficient CRC cells with colibactin selected a tolerant phenotype characterized by restoration of HR activity. Of translational relevance, colibactin-tolerant derivative cells acquired cross-resistance to SN38 and PARP inhibitor olaparib but not to oxaliplatin. Conclusion: Our results shed novel insight into colibactin’s genotoxic mechanism and support a model in which colibactin both promotes tumorigenesis and acts as an evolutionary bottleneck which selects HR proficient CRC cells. Furthermore, our study provides preclinical evidence on colibactin’s role in promoting chemoresistance in colorectal cancer. Citation Format: Alberto Sogari, Emanuele Rovera, Nicole Megan Reilly, Simona Lamba, Mariangela Russo, Annalisa Lorenzato, Erika Durinikova, Livio Trusolino, Sabrina Arena, Manuela Donalisio, Federica Di Nicolantonio, David Lembo, Alberto Bardelli. Tolerance to colibactin correlates with response to chemotherapeutic agents in colorectal cancer. [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 5900.

Molecular Analyses in Peritoneal Metastasis from Colorectal Cancer: A Review-An English Version.

Despite a trend showing continued improvement in survival by combing targeted agents in colorectal cancer, the improvement was limited, and clinically meaningful benefits were not achieved in peritoneal metastasis. The role of cytoreductive surgery (CRS) and proportion of the benefit from hyperthermic intraperitoneal chemotherapy (HIPEC) have been questioned. The PRODIGE 7 study aimed to assess the specific contribution of HIPEC to the survival benefit of peritoneal metastasis from colorectal cancer (CRC-PM) by grouping CRS alone versus CRS with oxaliplatin-based HIPEC, but failed to show any survival improvement. Of these criticisms, oxaliplatin resistance was suggested as the main cause of the negative result. In this regard, the relative resistance to oxaliplatin in consensus molecular subtype 4 colorectal cancer (CRC) is of great interest. Recent treatments for metastatic CRC have gradually moved to precision medicine based on individual biological information through high-throughput technology such as next generation sequencing. This review aimed to provide an overview of the current status of studies reporting the molecular knowledge of CRC-PM.

Saturated Fatty Acids in Cell Membrane Lipids Induce Resistance to 5-Fluorouracil in Colorectal Cancer Cells.

Resistance to chemotherapy is a major obstacle for patients with unresectable colorectal cancer (CRC); however, the factors that induce chemoresistance have not been elucidated. Lipid composition influences neoplastic behaviour. Therefore, this study examined whether lipid composition affects sensitivity to chemotherapeutic agents in CRC. We performed a lipidomic analysis of a CRC xenograft-derived spheroid model to identify potential relationships between the lipid profile and chemoresistance to 5-fluorouracil (5-FU). Genetic and pharmacological modulation of lipid synthesis were also used in the HCT-116 and DLD-1 CRC cell lines to further characterize resistance to 5-FU. Our lipidomic profiling revealed that phospholipids with saturated fatty acids (SFAs) were more abundant in 5-FU-resistant spheroids. The importance of phospholipids containing SFA in chemoresistance was confirmed by showing that in HCT-116 and DLD-1 cells, genetic or pharmacological inactivation of stearoyl-CoA desaturase-1, a key enzyme that converts SFAs to monounsaturated fatty acids, increased the proportion of SFAs in membranous phospholipids and reduced cell membrane fluidity, and this ultimately resulted in resistance to 5-FU. These data suggest that the saturated to monounsaturated fatty acid ratio in cellular membranous phospholipids affects sensitivity to chemotherapeutic agents.

Propofol Prevents the Growth, Migration, Invasion, and Glycolysis of Colorectal Cancer Cells by Downregulating Lactate Dehydrogenase Both In Vitro and In Vivo

Colorectal cancer (CRC) is one of the most frequently diagnosed gastrointestinal malignancies worldwide and has high rates of morbidity and mortality. Propofol has been reported to have certain anticancer properties. However, the role and mechanism of propofol in CRC are not entirely clear. CRC cells were treated with propofol and/or LDH-overexpression plasmids, and a mouse xenograft model of CRC was also established and treated with propofol. Cell viability, migration, and invasion were evaluated by CCK-8, wound healing, and transwell assays; the expression of related proteins was confirmed by western blotting; indexes of the glycolytic pathway were analyzed using specialized kits; tumor growth in mice was measured; pathological tissue structure was assessed by H&E staining; and 8-OHDG expression was determined by an immunochemistry assay. Our results verified that propofol could effectively prevent the malignant behaviors of CRC cells by suppressing cell viability, migration, and invasion and accelerating apoptosis. We also discovered that propofol could attenuate the glycolytic pathway in CRC cells. Moreover, we proved that lactate dehydrogenase (LDH) was required for the inhibitory effects of propofol on the growth of CRC cells, including glycolysis in CRC cells. Furthermore, our results showed that propofol could not only significantly inhibit tumor growth and glycolysis, but also ameliorate the pathological structure of CRC tumors. The current results proved that propofol could attenuate the malignant progression of CRC by preventing LDH activity, suggesting that propofol might be an effective therapeutic agent for CRC.

Sodium Tanshinone IIA Sulfonate as a Potent IDO1/TDO2 Dual Inhibitor Enhances Anti-PD1 Therapy for Colorectal Cancer in Mice.

Although the antitumor efficacy of immune checkpoint blockade (ICB) has been proved in colorectal cancer (CRC), the results are unsatisfactory, presumably owing to the presence of tryptophan metabolism enzymes indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase 2 (TDO2). However, only a few dual inhibitors for IDO1 and TDO2 have been reported. Here, we discovered that sodium tanshinone IIA sulfonate (STS), a sulfonate derived from tanshinone IIA (TSN), reduced the enzymatic activities of IDO1 and TDO2 with a half inhibitory concentration (IC50) of less than 10 μM using enzymatic assays for natural product screening. In IDO1- or TDO2- overexpressing cell lines, STS decreased kynurenine (kyn) synthesis. STS also reduced the percentage of forkhead box P3 (FOXP3) T cells in lymphocytes from the mouse spleen cocultured with CT26. In vivo, STS suppressed tumor growth and enhanced the antitumor effect of the programmed cell death 1 (PD1) antibody. Compared with anti-PD1 (α-PD1) monotherapy, combined with STS had lower level of plasma kynurenine. Immunofluorescence assay suggested that STS decreased the number of FOXP3+ T cells and increased the number of CD8+ T cells in tumors. Flow cytometry analysis of immune cells in tumor tissues demonstrated an increase in the percentage of tumor-infiltrating CD8+ T cells. According to our findings, STS acts as an immunotherapy agent in CRC by inhibiting both IDO1 and TDO2.

Evaluation of phenolic composition, antioxidant and cytotoxic activity of aronia melanocarpa leaf extracts.

The objective of this study was to investigate the phytochemical composition, antioxidant and cytotoxic potential of aronia leaf crude phenolic-extract (ACE) and purified phenolic-rich extract (APE) on human intestinal cells (CCD 841 CoN) and colon cancer cells (SW-480 and HT-29). UPLC-Q-TOF-MS analysis confirmed that aronia leaves are rich in structurally diverse polyphenols (25 and 42 compounds for ACE and APE, respectively). Chlorogenic acid and quercetin-3-rutinoside were most abundant in both aronia extracts. The sum of detected polyphenols varied significantly between extracts ranging from 32.8 mg/g (ACE) to 436.3 mg/g (APE). The biological potential of aronia extracts was confirmed by applying in vitro antioxidant and cytotoxic assays. The results of antioxidant activity (ABTS and FRAP) indicate that APE showed 2-fold stronger antioxidant properties compared to ACE. APE revealed a stronger cytotoxic effect on SW-480 and HT-29 cells than ACE (MTT test). After 48 -hours of incubation, APE was found to inhibit SW-480 cell growth by 50% vs. control at 194.35 μg/mL, while for HT-29 cells it was observed at 552.02 μg/mL. In the case of ACE, IC50 has not been reached for SW-480 cells after 48 -hours of treatment, but for HT-29 it was 794.84 μg/mL. Moreover, the viability was significantly decreased in a concentration- and time-dependent manner for both cancer cell lines. Examined extracts showed selective inhibitory potential against colon cancer cells. However, after 72 h incubation with CCD 841 CoN cells, the obtained IC50 values for APE and ACE were 594 μg/mL and 709 μg/mL respectively. This suggests that aronia leaves are valuable natural-based products that may support the treatment as chemopreventive agents in colorectal cancer.