Colorectal Cancer Cell Lines Research Articles

Liensinine sensitizes colorectal cancer cells to oxaliplatin by targeting HIF-1α to inhibit autophagy

BackgroundOxaliplatin is the most common chemotherapeutic agent for patients with colorectal cancer. However, its anti-cancer efficacy is restricted by drug resistance occurring through several mechanisms, including autophagy. Liensinine exerts a considerable anti-tumor effect and can regulate autophagy. Inhibition of autophagy is a strategy to reverse resistance to oxaliplatin. The aim of this study was to check if liensinine can enhance the therapeutic efficacy of oxaliplatin in colorectal cancer and if so, elucidate its mechanism. MethodsTwo colorectal cancer cell lines, HCT116 and LoVo, and one normal intestinal epithelial cell, NCM-460 were used for in vitro experiments. Cell Counting Kit-8 (CCK-8), colony formation, and flow cytometry assays were used to evaluate the cytotoxicity of liensinine and oxaliplatin. Network pharmacology analysis and Human XL Oncology Array were used to screen targets of liensinine. Transfections and autophagy regulators were used to confirm these targets. The relationship between the target and clinical effect of oxaliplatin was analyzed. Patient-derived xenograft (PDX) models were used to validate the effects of liensinine and oxaliplatin. ResultsCCK-8 and colony formation assays both showed that the combination treatment of liensinine and oxaliplatin exerted synergistic effects. Results of the network pharmacology analysis and Human XL Oncology Array suggested that liensinine can inhibit autophagy by targeting HIF-1α/eNOS. HIF-1α was identified as the key factor modulated by liensinine in autophagy and induces resistance to oxaliplatin. HIF-1α levels in tumor cells and prognosis for FOLFOX were negatively correlated in clinical data. The results from three PDX models with different HIF-1α levels showed their association with intrinsic and acquired resistance to oxaliplatin in these models, which could be reversed by liensinine. ConclusionsResearch on the relationship between HIF-1α levels and the clinical effect of oxaliplatin is lacking, and whether liensinine regulates HIF-1α is unknown. Our findings suggest that liensinine overcomes the resistance of colorectal cancer cells to oxaliplatin by suppressing HIF-1α levels to inhibit autophagy. Our findings can contribute to improving prognosis following colorectal cancer therapy.

Identification and validation of cuproptosis and disulfidptosis related genes in colorectal cancer

Colorectal cancer, the third most prevalent malignant cancer, is associated with poor prognosis. Recent studies have investigated the mechanisms underlying cuproptosis and disulfidptosis in colorectal cancer. However, whether genes linked to these processes impact the prognosis of colorectal cancer patients through analogous mechanisms remains unclear. In this study, we developed a model of cuproptosis and disulfidptosis in colorectal cancer and concurrently explored the role of the pivotal model gene HSPA8 in colorectal cancer cell lines. Our results revealed a positive correlation between cuproptosis and disulfidptosis, both of which are emerging as protective factors for the prognosis of CRC patients. Consequently, a prognostic model encompassing HSPA8, PDCL3, CBX3, ATP6V1G1, TAF1D, RPL4, and RPL14 was constructed. Notably, the key gene in our model, HSPA8, exhibited heightened expression and was validated as a protective prognostic factor in colorectal cancer, exerting inhibitory effects on colorectal cancer cell proliferation. This study offers novel insights into the interplay between cuproptosis and disulfidptosis. The application of the prognostic model holds promise for more effectively predicting the overall survival of colorectal cancer patients.

MRI-traceable multifunctional magnetic mesoporous silica nanoparticles (MMSN) capped with graphene quantum dots (GQD) as a theragnostic system in colorectal cancer treatment

In the study, a multifunctional nanosystem composed of magnetic core-mesoporous silica nanoparticles (MMSN) capped with graphene quantum dots (GQD) was proposed as a theragnostic platform against colorectal cancer cells. The theragnostic carrier was well characterized and had an average particle size of 140 nm, with a specific surface of 475.82 m2 g−1. The superparamagnetic nanoparticles showed a hysteresis loop, with a maximum magnetization of 14.93 emu.g−1 and a remanence of 2.64 emu.g−1. The functionalization of MMSN was confirmed using the ninhydrin test. Regorafenib (REGO), an anticancer drug, was used with a loading capacity of 77.5 μg mg−1. The drug release profiles from the carrier and the sensitivity of the interaction between MMSN and GQD to pH were examined, revealing that more drug release was observed in acidic pH. The cytotoxicity of the MMSN-REGO/GQD system was evaluated on colorectal cancer cell line SW-480 using MTT assay, and the results indicated that no cytotoxicity was observed for the MMSN/GQD carrier. Furthermore, the IC50 of REGO was significantly reduced from 85 μg ml−1 to 6 μg ml−1 in the loaded form. The response of MMSN/GQD nanoparticles to the external magnetic field exhibited the capability of the theragnostic system as an MRI contrast agent. Generally, biocompatible, theragnostic, pH-responsive, multifunctional MMSN/GQD can be considered promising candidates for treatment, MRI imaging, and hyperthermia in colorectal cancer treatment.

Knockdown of SETD5 Inhibits Colorectal Cancer Cell Growth and Stemness by Regulating PI3K/AKT/mTOR Pathway.

SET domain-containing 5 (SETD5), a member of protein lysine methyltransferase family, is expressed in multiple cancers, making it potential therapeutic targets. However, the role of SETD5 in colorectal cancer remains largely unknown. The expression of SETD5 in the 30 pairs colorectal cancer tissues samples and cell lines were determined by qRT-PCR. The functions of SETD5 was detected by knocked-down or overexpression in colorectal cancer cell lines SW480 and HCT116 cells. Cell proliferative activity, cell death, and stemness characteristics were assessed. BEZ235, a PI3K/AKT/mTOR pathway inhibitor, was used to perform rescue experiment to analyze whether SETD5 exerted its effects through activating PI3K/AKT/mTOR pathway. SETD5 was substantially upregulated in colorectal cancer, and correlated to metastasis and clinical stage of patients. Knockdown of SETD5 inhibited SW480 and HCT116 cell growth, as evidenced by the inhibition of cell viability and clone-forming. Moreover, Knockdown of SETD5 suppressed the capability of tumor sphere formation of SW480 and HCT116 cells, and reduced the expression of stemness-related proteins Nanog and Sox2. Further western blot analysis revealed that SETD5 knockdown inhibited the phosphorylation of proteins associated with the PI3K/AKT/mTOR pathway. In contrast, overexpression of SETD5 exerted the opposite effects. Mechanistically, by blocking PI3K/AKT/mTOR pathway with BEZ235, the effects of SETD5 overexpression on cell viability and Nanog and Sox2 protein expression were reversed. Our results substantiated that SETD5 functioned as an oncogene by promoting cell growth and stemness in colorectal cancer cells through activating the PI3K/AKT/mTOR signaling pathway.

C16, a PKR inhibitor, suppresses cell proliferation by regulating the cell cycle via p21 in colorectal cancer

Double-stranded RNA-activated protein kinase R (PKR) is highly expressed in colorectal cancer (CRC). However, the role of PKR in CRC remains unclear. The aim of this study was to clarify whether C16 (a PKR inhibitor) exhibits antitumor effects and to identify its target pathway in CRC. We evaluated the effects of C16 on CRC cell lines using the MTS assay. Enrichment analysis was performed to identify the target pathway of C16. The cell cycle was analyzed using flow cytometry. Finally, we used immunohistochemistry to examine human CRC specimens. C16 suppressed the proliferation of CRC cells. Gene Ontology (GO) analysis revealed that the cell cycle-related GO category was substantially enriched in CRC cells treated with C16. C16 treatment resulted in G1 arrest and increased p21 protein and mRNA expression. Moreover, p21 expression was associated with CRC development as observed using immunohistochemical analysis of human CRC tissues. C16 upregulates p21 expression in CRC cells to regulate cell cycle and suppress tumor growth. Thus, PKR inhibitors may serve as a new treatment option for patients with CRC.

Targeting Colorectal Cancer: Unravelling the Transcriptomic Impact of Cisplatin and High-THC Cannabis Extract.

Cisplatin and other platinum-derived chemotherapy drugs have been used for the treatment of cancer for a long time and are often combined with other medications. Unfortunately, tumours often develop resistance to cisplatin, forcing scientists to look for alternatives or synergistic combinations with other drugs. In this work, we attempted to find a potential synergistic effect between cisplatin and cannabinoid delta-9-THC, as well as the high-THC Cannabis sativa extract, for the treatment of HT-29, HCT-116, and LS-174T colorectal cancer cell lines. However, we found that combinations of the high-THC cannabis extract with cisplatin worked antagonistically on the tested colorectal cancer cell lines. To elucidate the mechanisms of drug interactions and the distinct impacts of individual treatments, we conducted a comprehensive transcriptomic analysis of affected pathways within the colorectal cancer cell line HT-29. Our primary objective was to gain a deeper understanding of the underlying molecular mechanisms associated with each treatment modality and their potential interactions. Our findings revealed an antagonistic interaction between cisplatin and high-THC cannabis extract, which could be linked to alterations in gene transcription associated with cell death (BCL2, BAD, caspase 10), DNA repair pathways (Rad52), and cancer pathways related to drug resistance.

Ultrasound-assisted extraction of quinoa seed malt extract for the determination of nutritional content, antioxidant, and anticancer activity against HT-29 colorectal cancer cell lines

Ultrasound-assisted extraction of quinoa seed malt extract for the determination of nutritional content, antioxidant, and anticancer activity against HT-29 colorectal cancer cell lines

Development of a Human B7-H3-Specific Antibody with Activity against Colorectal Cancer Cells through a Synthetic Nanobody Library.

Nanobodies have emerged as promising tools in biomedicine due to their single-chain structure and inherent stability. They generally have convex paratopes, which potentially prefer different epitope sites in an antigen compared to traditional antibodies. In this study, a synthetic phage display nanobody library was constructed and used to identify nanobodies targeting a tumor-associated antigen, the human B7-H3 protein. Combining next-generation sequencing and single-clone validation, two nanobodies were identified to specifically bind B7-H3 with medium nanomolar affinities. Further characterization revealed that these two clones targeted a different epitope compared to known B7-H3-specific antibodies, which have been explored in clinical trials. Furthermore, one of the clones, dubbed as A6, exhibited potent antibody-dependent cell-mediated cytotoxicity (ADCC) against a colorectal cancer cell line with an EC50 of 0.67 nM, upon conversion to an Fc-enhanced IgG format. These findings underscore a cost-effective strategy that bypasses the lengthy immunization process, offering potential rapid access to nanobodies targeting unexplored antigenic sites.

Abstract P52: Combination of 5-fluorouracil and Menadione Exerts Synergistic Effect on Colorectal Cancer Cells by Targeting Wnt/β-catenin Signaling Pathway

Abstract Colorectal cancer is the third most common type of cancer and the second most in terms of mortality rate worldwide. 5-fluorouracil (5-FU), the fluoropyrimidine drug, that interferes with DNA replication and repair processes, is the first-line-of-treatment against colorectal cancer. However, cells gain resistance over time and relapses occur upon continuous 5-FU therapy. Interestingly, 5-FU promotes stemness in colorectal cancer via Wnt signaling pathway which is critical for its progression. Studies have pointed out the possibility of using a Wnt signaling inhibitor along with 5-FU as a better strategy to overcome the poor outcomes of current 5-FU based therapies. We have previously shown that menadione (vitamin K3) suppresses Wnt signaling pathway in colorectal cancer cells. In the present study, we attempted to evaluate if the combination of menadione and 5-FU can exert a synergistic effect in the human colorectal cancer cell lines HCT116 and SW620. Analysis of the cell viability assay results using CompuSyn software confirmed that the combination indeed acts synergistically. The combination efficiently downregulated the expression of the Wnt signal transducer protein, β-catenin, and the expression of other proteins in the pathway such as phospho-GSK3β in the cell lines HCT116 and SW620. Docking of the individual drugs and their combination on β-catenin using Autodock Vina showed that 5-FU and menadione in combination bind to key protein-protein interaction (PPI) sites of β-catenin whereby they may inhibit β-catenin-TCF interaction or activate the β-catenin destruction complex. Taken together, our data possibly explains that the synergistic action of 5-FU and menadione in colorectal cancer cells may be due to the simultaneous binding of the two drugs to multiple PPI sites thereby blocking the activity of β-catenin. Citation Format: Vidya P Warrier, Sankaran Venkatachalam, Sakthivel Ramasamy, M Michael Gromiha, Devarajan Karunagaran. Combination of 5-fluorouracil and Menadione Exerts Synergistic Effect on Colorectal Cancer Cells by Targeting Wnt/β-catenin Signaling Pathway [abstract]. In: Proceedings of Frontiers in Cancer Science; 2023 Nov 6-8; Singapore. Philadelphia (PA): AACR; Cancer Res 2024;84(8_Suppl):Abstract nr P52.

UBXN11 Predicts as a Poor Index for Colorectal Cancer and Contributes to the Tumorigenesis by Activating NF-κB Signaling.

The complex mechanisms of colorectal cancer (CRC) pathogenesis and progression remain poorly understood. This study endeavors to unravel the role of UBXN11within the context of CRC. UBXN11 expression level in CRC, stomach adenocarcinoma and esophageal carcinoma, and the overall survival in corresponding cancers were analyzed using UALCAN database. Human CRC cell lines and xenograft mouse model with UBXN11 overexpression were established to investigate the pathological role of UBXN11 in CRC progression. Luciferase assay, qPCR, and Western blot were performed to dissect the interaction between UBXN11 and NF-κB signaling. Heightened UBXN11 expression was observed in various digestive tract tumors, which was positively correlated with the reduced overall survival rates in CRC patients. Overexpression of UBXN11 significantly enhanced CRC cell proliferation in vitro and promoted tumor growth in vivo. Mechanistically, UBXN11 promoted CRC tumorigenesis through increasing the activation of NF-κB signaling pathway. This study underscores the pivotal role of UBXN11 in CRC progression and paves the way for novel therapeutic strategies for CRC treatment.

Upregulated lncRNA PRNT promotes progression and oxaliplatin resistance of colorectal cancer cells by regulating HIPK2 transcription.

Colorectal cancer (CRC) is the third most common cancer and a significant cause of cancer-related mortality globally. Resistance to chemotherapy, especially during CRC treatment, leads to reduced effectiveness of drugs and poor patient outcomes. Long noncoding RNAs (lncRNAs) have been implicated in various pathophysiological processes of tumor cells, including chemotherapy resistance, yet the roles of many lncRNAs in CRC remain unclear. To identify and analyze the lncRNAs involved in oxaliplatin resistance in CRC and to understand the underlying molecular mechanisms influencing this resistance. Gene Expression Omnibus datasets GSE42387 and GSE30011 were reanalyzed to identify lncRNAs and mRNAs associated with oxaliplatin resistance. Various bioinformatics tools were employed to elucidate molecular mechanisms. The expression levels of lncRNAs and mRNAs were assessed via quantitative reverse transcription-polymerase chain reaction. Functional assays, including MTT, wound healing, and Transwell, were conducted to investigate the functional implications of lncRNA alterations. Interactions between lncRNAs and transcription factors were examined using RIP and luciferase reporter assays, while Western blotting was used to confirm downstream pathways. Additionally, a xenograft mouse model was utilized to study the in vivo effects of lncRNAs on chemotherapy resistance. LncRNA prion protein testis specific (PRNT) was found to be upregulated in oxaliplatin-resistant CRC cell lines and negatively correlated with homeodomain interacting protein kinase 2 (HIPK2) expression. PRNT was demonstrated to sponge transcription factor zinc finger protein 184 (ZNF184), which in turn could regulate HIPK2 expression. Altered expression of PRNT influenced CRC cell sensitivity to oxaliplatin, with overexpression leading to decreased sensitivity and decreased expression reducing resistance. Both RIP and luciferase reporter assays indicated that ZNF184 and HIPK2 are targets of PRNT. The PRNT/ZNF184/HIPK2 axis was implicated in promoting CRC progression and oxaliplatin resistance both in vitro and in vivo. The study concludes that PRNT is upregulated in oxaliplatin-resistant CRC cells and modulates the expression of HIPK2 by sponging ZNF184. This regulatory mechanism enhances CRC progression and resistance to oxaliplatin, positioning PRNT as a promising therapeutic target for CRC patients undergoing oxaliplatin-based chemotherapy.

MicroRNA-298 determines the radio-resistance of colorectal cancer cells by directly targeting human dual-specificity tyrosine(Y)-regulated kinase 1A.

Radiotherapy stands as a promising therapeutic modality for colorectal cancer (CRC); yet, the formidable challenge posed by radio-resistance significantly undermines its efficacy in achieving CRC remission. To elucidate the role played by microRNA-298 (miR-298) in CRC radio-resistance. To establish a radio-resistant CRC cell line, HT-29 cells underwent exposure to 5 gray ionizing radiation that was followed by a 7-d recovery period. The quantification of miR-298 levels within CRC cells was conducted through quantitative RT-PCR, and protein expression determination was realized through Western blotting. Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and proliferation by clonogenic assay. Radio-induced apoptosis was discerned through flow cytometry analysis. We observed a marked upregulation of miR-298 in radio-resistant CRC cells. MiR-298 emerged as a key determinant of cell survival following radiation exposure, as its overexpression led to a notable reduction in radiation-induced apoptosis. Intriguingly, miR-298 expression exhibited a strong correlation with CRC cell viability. Further investigation unveiled human dual-specificity tyrosine(Y)-regulated kinase 1A (DYRK1A) as miR-298's direct target. Taken together, our findings underline the role played by miR-298 in bolstering radio-resistance in CRC cells by means of DYRK1A downregulation, thereby positioning miR-298 as a promising candidate for mitigating radio-resistance in CRC.

PREX2 contributes to radiation resistance by inhibiting radiotherapy-induced tumor immunogenicity via cGAS/STING/IFNs pathway in colorectal cancer

BackgroundColorectal cancer (CRC) lacks established biomarkers or molecular targets for predicting or enhancing radiation response. Phosphatidylinositol-3,4,5-triphosphate-dependent Rac exchange factor 2 (PREX2) exhibits intricate implications in tumorigenesis and progression. Nevertheless, the precise role and underlying mechanisms of PREX2 in CRC radioresistance remain unclear.MethodsRNA-seq was employed to identify differentially expressed genes between radioresistant CRC cell lines and their parental counterparts. PREX2 expression was scrutinized using Western blotting, real-time PCR, and immunohistochemistry. The radioresistant role of PREX2 was assessed through in vitro colony formation assay, apoptosis assay, comet assay, and in vivo xenograft tumor models. The mechanism of PREX2 was elucidated using RNA-seq and Western blotting. Finally, a PREX2 small-molecule inhibitor, designated PREX-in1, was utilized to enhance the efficacy of ionizing radiation (IR) therapy in CRC mouse models.ResultsPREX2 emerged as the most significantly upregulated gene in radioresistant CRC cells. It augmented the radioresistant capacity of CRC cells and demonstrated potential as a marker for predicting radioresistance efficacy. Mechanistically, PREX2 facilitated DNA repair by upregulating DNA-PKcs, suppressing radiation-induced immunogenic cell death, and impeding CD8+ T cell infiltration through the cGAS/STING/IFNs pathway. In vivo, the blockade of PREX2 heightened the efficacy of IR therapy.ConclusionsPREX2 assumes a pivotal role in CRC radiation resistance by inhibiting the cGAS/STING/IFNs pathway, presenting itself as a potential radioresistant biomarker and therapeutic target for effectively overcoming radioresistance in CRC.

Mediator kinase module proteins, genetic alterations and expression of super-enhancer regulated genes in colorectal cancer.

Genetic alterations are well characterized as contributors to the pathogenesis of cancers. Epigenetic abnormalities can lead to perturbations of the expression of genes in cancer cells without structural defects. Deregulation of proteins of the transcription machinery may result in perturbations of target genes. Mediator, a multiprotein component of the transcription machinery facilitates the function of RNA polymerase II, which transcribes most human genes. A part of the mediator with kinase activity, called the Mediator kinase module shows genetic alterations in a sub-set of colorectal cancers. Data from publicly available genomic series of colorectal cancer patients were examined to determine alterations of Mediator kinase module component genes, including MED12, MED12L, MED13, MED13L, CDK8, CDK19, and CCNC. The prevalence of alterations in genomically defined colorectal cancer sub-sets was also interrogated. The effect of Mediator kinase module member gene expression on colorectal cancer relapse-free survival was investigated. Mutations in genes of the Mediator kinase module were present in a small percentage of colorectal cancers, ranging between 2 to 10% for MED12 and MED13 and alternative units MED12L and MED13L and below 2% for kinases CDK8 and CDK19 and cyclin C. Amplifications of the CDK8 gene were observed in 3% to 5% of colorectal cancers. The highest prevalence of mutations was observed in MSI cancers and the equivalent CMS1 group, with other genomic groups showing much lower frequency. An association of higher expression of MED12 with inferior relapse-free survival was observed. In contrast, higher expression of cyclin C was associated with improved survival. Colorectal cancer cell lines with CDK8 amplifications displayed sensitivity to several small molecule inhibitors of the KRAS/PI3K pathway but not to BET inhibitors. The Mediator kinase module is deregulated in a sub-set of colorectal cancers with differences observed in genomically defined groups. These variations may result in differences in sensitivity to targeted therapies and may have to be taken into consideration as such therapies are developed.

CBC-1 as a Cynanbungeigenin C derivative inhibits the growth of colorectal cancer through targeting Hedgehog pathway component GLI 1

Colorectal cancer (CRC) is one of the most common gastrointestinal cancers that results in death in worldwide. The Hedgehog (HH) signalling pathway regulates the initiation and progression of CRC. Inhibiting the HH pathway has been presented as a potential treatment strategy in recent years. Cynanbungeigenin C (CBC) is a new type of C21 steroid that has been previously reported for the treatment of medulloblastoma. However, its further investigation was limited by its poor water solubility. In this study, six new CBC derivatives were synthesized through the structural modification of CBC, and four of them showed better water solubility than CBC. Moreover, their antiproliferative activities on CRC were evaluated. It was found that CBC-1 presented the best inhibitory effect on three types of CRC cell lines, and this effect was superior to that of CBC. Mechanistically, CBC-1 inhibited the proliferation of CRC cells through regulation of mRNA and proteins of the HH pathway according to qRT–PCR and Western blotting analysis. Furthermore, Cellular Thermal Shift Assay results indicated that CBC-1 regulated this signalling pathway by targeting glioma‑associated oncogene (GLI 1).In addition, cell apoptosis was induced increasingly by transfection with GLI 1 siRNA or treatment with CBC-1 to downregulate GLI 1. Last, the in vivo results demonstrated that CBC-1 significantly reduced tumour size and downregulated GLI 1 in CRC. Therefore, this study suggests that CBC-1, a new GLI 1 inhibitor derived from natural products, may be developed as a potential antitumour candidate for CRC treatment.

Dexmedetomidine promotes colorectal cancer progression via Piwil2 signaling.

α2-adrenoceptor agonist dexmedetomidine (DEX) has been reported to promote tumorigenesis. Stem-cell protein Piwil2 is associated with cancer progression. Whether Piwil2 plays a role in tumor-promoting effects of DEX is unknown. We examined the expression of Piwil2 in human colorectal cancer (CRC) cell lines with/without DEX treatment. We also studied the roles of Piwil2 in proliferation, invasion, migration, as well as expressions of epithelial-mesenchymal transition (EMT)-related proteins in DEX-treated in vitro and in vivo CRC models. And the experiments with genetic and pharmacological treatments were conducted to investigate the underlying molecular mechanism. RNA-sequencing (RNA-seq) analysis found Piwil2 is one of most upregulated genes upon DEX treatment in CRC cells. Furthermore, Piwil2 protein levels significantly increased in DEX-treated CRC cancer cells, which promoted proliferation, invasion, and migration in both CRC cell lines and human tumor xenografts model. Mechanistically, DEX increased nuclear factor E2-related factor 2 (Nrf2) expression, which enhanced Piwil2 transcription via binding to its promoter. Furthermore, in vitro experiments with Piwil2 knockdown or Siah2 inhibition indicated that DEX promoted EMT process and tumorigenesis through Siah2/PHD3/HIF1α pathway. The experiments with another α2-adrenoceptor agonist Brimonidine and antagonists yohimbine and atipamezole also suggested the role of Piwil2 signaling in tumor-promoting effects via an α2 adrenoceptor-dependent manner. DEX promotes CRC progression may via activating α2 adrenoceptor-dependent Nrf2/Piwil2/Siah2 pathway and thus EMT process. Our work provides a novel insight into the mechanism underlying tumor-promoting effects of α2-adrenoceptor agonists.

Wnt, glucocorticoid and cellular prion protein cooperate to drive a mesenchymal phenotype with poor prognosis in colon cancer

BackgroundThe mesenchymal subtype of colorectal cancer (CRC), associated with poor prognosis, is characterized by abundant expression of the cellular prion protein PrPC, which represents a candidate therapeutic target. How PrPC is induced in CRC remains elusive. This study aims to elucidate the signaling pathways governing PrPC expression and to shed light on the gene regulatory networks linked to PrPC.MethodsWe performed in silico analyses on diverse datasets of in vitro, ex vivo and in vivo models of mouse CRC and patient cohorts. We mined ChIPseq studies and performed promoter analysis. CRC cell lines were manipulated through genetic and pharmacological approaches. We created mice combining conditional inactivation of Apc in intestinal epithelial cells and overexpression of the human prion protein gene PRNP. Bio-informatic analyses were carried out in two randomized control trials totalizing over 3000 CRC patients.ResultsIn silico analyses combined with cell-based assays identified the Wnt-β-catenin and glucocorticoid pathways as upstream regulators of PRNP expression, with subtle differences between mouse and human. We uncover multiple feedback loops between PrPC and these two pathways, which translate into an aggravation of CRC pathogenesis in mouse. In stage III CRC patients, the signature defined by PRNP-CTNNB1-NR3C1, encoding PrPC, β-catenin and the glucocorticoid receptor respectively, is overrepresented in the poor-prognosis, mesenchymal subtype and associates with reduced time to recurrence.ConclusionsAn unleashed PrPC-dependent vicious circle is pathognomonic of poor prognosis, mesenchymal CRC. Patients from this aggressive subtype of CRC may benefit from therapies targeting the PRNP-CTNNB1-NR3C1 axis.

Extraction and characterization of R-phycoerythrin from wet and lyophilized macroalgae Solieria filiformis by pressurized water method

The present study evaluated the production of R-phycoerythrin (R-PE) extracted from the macroalgae Solieria filiformis through a green technology (pressurized water method). The extraction process over time and the macroalgae structure were analyzed. Two samples (freeze-dried and wet biomass, with 1 % and 10 % m/v, respectively) were studied at pressures up to 500 bar. R-PE maximum yield was reached for lyophilized seaweed structure after 360 min, obtaining 0.67 mg of R-PE per gram of dry biomass. In contrast, wet biomass reached 0.05 mg of R-PE per gram of wet biomass. Crude and precipitated extracts were characterized using the following techniques: electrophoresis, circular dichroism, and FTIR. The carbohydrate content was also determined. The biomolecule showed R-PE characteristic spectra, fluorescence, and α-helix structure as the main element of its secondary structure (93.28–95.24 %), indicating the presence of other proteins in the precipitated extract. Precipitated extract's cytotoxic activity was assessed through an MTT assay against tumor cell lines of colorectal cancer (HCT116), prostate cancer (PC3), glioblastoma cancer (SNB-19), and HL60 (promyeloblast leukemia). The most prominent in vitro results were in HL-60 and HCT-116 cell lines.

The HSP90AB1-mediated upregulation of IDO1 can promote the progression of colorectal cancer

Abstract Objectives Colorectal cancer (CRC) is a global challenge, and heat shock protein 90 (HSP90) is identified as a key driver in cancer progression. However, the tumor-promoting mechanism of HSP90 in CRC, particularly HSP90AB1, remains unclear. This study aims to explore and analyze the oncogenic mechanism of HSP90AB1 in CRC and identify potential therapeutic targets. Materials and methods HSP90AB1 expression underwent analysis in CRC cell lines and tissues at mRNA and protein levels. Through the use of shRNA, targeted suppression of HSP90AB1 was achieved in CRC cell lines, enabling analysis of its influence on cell proliferation, invasion, apoptosis, and cell cycle progression. Subsequent investigation focused on elucidating the regulatory relationship between HSP90AB1 and IDO1, employing a combination of bioinformatics approaches and in vitro/vivo experiments. These efforts confirmed IDO1 as a downstream target of HSP90AB1 and provided insight into its role in driving CRC progression. Results HSP90AB1 exhibits overexpression in both CRC cell lines and tumor tissues (p<0.05). Its downregulation impedes cell proliferation and invasion (p<0.01), promotes apoptosis and cell cycle arrest (p<0.05). Investigation reveals that decreased HSP90AB1 leads to the inhibition of IDO1 (p<0.01), suggesting that IDO1 regulation plays a crucial role in mediating the pro-tumorigenic effects of HSP90AB1. In vivo experiments confirm the substantial reduction in tumor growth upon HSP90AB1 knockdown in xenograft models (p<0.01). However, this tumor-suppressive effect is reversed upon IDO1 overexpression (p<0.01), highlighting IDO1 as a downstream target of HSP90AB1 in CRC progression. Conclusions HSP90AB1 exerts a regulatory role in the progression of CRC by upregulating IDO1.

Abstract LB046: Treatment of EGFR-mediated tumors via lysosome activity regulation

Abstract The lysosome is a membrane-enclosed organelle that is an essential part of the cell's digestive system. This organelle contains over 60 types of hydrolases that can break down biological polymers such as proteins, carbohydrates, lipids, and nucleic acids. These enzymes require an acidic pH for optimal function, which is achieved by using ATP hydrolysis to pump protons against their electrochemical gradient into the lysosome by the vacuolar H+ ATPase (V-ATPase). The biogenesis of lysosomes is known to be controlled by the coordination of the regulatory gene network and the lysosomal expression, which is governed by the nuclear translocation of transcription factor EB (TFEB). Lysosomes are an essential component of the inner membrane system and participate in numerous cell biological processes, such as macromolecular degradation, antigen presentation, intracellular pathogen destruction, plasma membrane repair, exosome release, cell adhesion/migration, and apoptosis. The primary function of lysosomes is to digest extracellular material that has been internalized by endocytosis and intracellular components that have been sequestered by autophagy. They recycle the unwanted cellular material as energy, providing a nutrient source for maintaining cellular homeostasis. Lysosomal activity affects the tumor microenvironment, making the tumor cells use energy more efficiently, and it is known to be increased compared to neighboring normal tissues. However, recent studies have shown that increased lysosomal activity can lead to downregulating Receptor tyrosine kinase (RTK) activity in cancer cells. RTK activity frequently occurs with mutations in EGFR in various human cancers. Thus, EGFR is currently a target for several cancer therapies. Recently, studies on EGFR-mediated tumors through lysosome regulation have been continuously conducted. According to our previous study, it has been found that lysosome inactivation suppresses the degradation of RKT, such as EGFR, and increases the expression of EGFR.EGFR is expressed in various human tumors, including gliomas and carcinomas of the lung, colon, head and neck, pancreas, breast, ovary, and kidney. Mutations, gene amplification, and protein overexpression of various pathway elements contribute to carcinogenesis and impact prognosis. Alterations within the EGFR signaling cascade, such as gene mutations, gene amplification, and protein overexpression, have been shown to contribute to colorectal carcinogenesis.[4]In this study, we will down-regulate the expression of EGFR by activating the lysosome in DLD-1, a colorectal cancer cell line. Lysosome was activated by overexpression of V-ATPase using the lentiviral system. In vitro experiments confirmed that the degradation of EGFR was actively performed in the lysosome-activated experimental group. It inhibited cancer cells' proliferation, survival, and differentiation. Targeting lysosomes may be a new approach to overcoming EGFR-mediated cancers. Citation Format: Dohyang Kim, Anlin Zhu, Jaewoo Hong. Treatment of EGFR-mediated tumors via lysosome activity regulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB046.