Drug-resistant Colon Cancer Research Articles

CTHRC1 is associated with BRAF(V600E) mutation and correlates with prognosis, immune cell infiltration, and drug resistance in colon cancer, thyroid cancer, and melanoma.

Colon cancer, thyroid cancer, and melanoma are common malignant tumors that seriously threaten human health globally. The B-Raf proto-oncogene, serine/threonine kinase (BRAF)(V600E) mutation is an important driver gene mutation in these cancer types. In this study, we identified that collagen triple helix repeat containing 1 (CTHRC1) expression was associated with the BRAF(V600E) mutation in colon cancer, thyroid cancer, and melanoma. Based on database analysis and clinical tissue studies, CTHRC1 was verified to correlate with poor prognosis and worse clinicopathological features in colon cancer and thyroid cancer patients, but not in patients with melanoma. Several signaling pathways, immune cell infiltration, and immunotherapy markers were associated with CTHRC1 expression. Additionally, a high level of CTHRC1 was correlated with decreased sensitivity to antitumor drugs (vemurafenib, PLX-4720, dabrafenib, and SB-590885) targeting the BRAF(V600E) mutation. This study provides evidence of a significant correlation between CTHRC1 and the BRAF(V600E) mutation, suggesting its potential utility as a diagnostic and prognostic biomarker in human colon cancer, thyroid cancer, and melanoma.

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.

Targeted delivery of FAK siRNA by engineered exosomes to reverse cetuximab resistance via activating paraptosis in colon cancer

BackgroundCetuximab is extensively used in the treatment of metastatic colorectal cancer (mCRC). However, resistance poses a significant challenge to successful therapy. Recently, paraptosis, a non-classical programmed cell death, has garnered increased attention for its potential application value in antitumor treatments. We aimed to identify the essential pathways and signaling molecules involved in paraptosis inhibition and select them as therapeutic targets in cetuximab resistance. Additionally, engineered exosome technology is used as a drug delivery system with both targeted and effector properties.ResultsBy comparing the differential expression of paraptosis-related genes between drug-resistant colon cancer cells and sensitive cells, it was observed that the paraptosis level induced by cetuximab was significantly downregulated in drug-resistant cells. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis identified the focal adhesion kinase (FAK) signaling pathway as a key pathway involved in the suppression of paraptosis. The biological function of FAK in cetuximab-resistant cells was investigated through cell morphology observation, CCK-8 assay, colony formation assay, RT-qPCR, Western Blot, and loss-of-function experiments. The results showed that the FAK signaling pathway was significantly upregulated in cetuximab-resistant colon cancer cells, and siRNA interference targeting FAK could notably inhibit cell proliferation while upregulating the paraptosis level. Based on this, engineered colon cancer cells targeted and FAK siRNA loaded exosomes (CT-Exo-siFAK1) were constructed. In vitro experiments, CT-Exo-siFAK1 could effectively activate paraptosis and inhibit the proliferation of drug-resistant colon cancer cells. In vivo experiments also confirmed that CT-Exo-siFAK1 significantly suppressed tumor growth and metastasis while upregulating the paraptosis level.ConclusionThis study suggests that FAK signaling pathway-mediated inhibition of paraptosis levels is crucial in the sensitivity of cetuximab targeted therapy in colon cancer, and the use of engineered exosomes to deliver FAK siRNA may be an effective strategy to reverse cetuximab resistance.

Network-based elucidation of colon cancer drug resistance mechanisms by phosphoproteomic time-series analysis

Aberrant signaling pathway activity is a hallmark of tumorigenesis and progression, which has guided targeted inhibitor design for over 30 years. Yet, adaptive resistance mechanisms, induced by rapid, context-specific signaling network rewiring, continue to challenge therapeutic efficacy. Leveraging progress in proteomic technologies and network-based methodologies, we introduce Virtual Enrichment-based Signaling Protein-activity Analysis (VESPA)—an algorithm designed to elucidate mechanisms of cell response and adaptation to drug perturbations—and use it to analyze 7-point phosphoproteomic time series from colorectal cancer cells treated with clinically-relevant inhibitors and control media. Interrogating tumor-specific enzyme/substrate interactions accurately infers kinase and phosphatase activity, based on their substrate phosphorylation state, effectively accounting for signal crosstalk and sparse phosphoproteome coverage. The analysis elucidates time-dependent signaling pathway response to each drug perturbation and, more importantly, cell adaptive response and rewiring, experimentally confirmed by CRISPR knock-out assays, suggesting broad applicability to cancer and other diseases.

Natural small-molecules reverse Xeroderma Pigmentosum Complementation Group C (XPC) deficient-mediated drug-resistance in renal cell carcinoma

BackgroundRenal cancer is insensitive to radiotherapy or most chemotherapies. While the loss of the XPC gene was correlated with drug resistance in colon cancer, the expression of XPC and its role in the drug resistance of renal cancer have not yet been elucidated. With the fact that natural small-molecules have been adopted in combinational therapy with classical chemotherapeutic agents to increase the drug sensitivity and reduce adverse effects, the use of herbal compounds to tackle drug-resistance in renal cancer is advocated. PurposeTo correlate the role of XPC gene deficiency to drug-resistance in renal cancer, and to identify natural small-molecules that can reverse drug-resistance in renal cancer via up-regulation of XPC. MethodsIHC was adopted to analyze the XPC expression in human tumor and adjacent tissues. Clinical data extracted from The Cancer Genome Atlas (TCGA) database were further analysed to determine the relationship between XPC gene expression and tumor staging of renal cancer. Two types of XPC-KD renal cancer cell models were established to investigate the drug-resistant phenotype and screen XPC gene enhancers from 134 natural small-molecules derived from herbal plants. Furthermore, the identified XPC enhancers were verified in single or in combination with FDA-approved chemotherapy drugs for reversing drug-resistance in renal cancer using MTT cytotoxicity assay. Drug resistance gene profiling, ROS detection assay, immunocytochemistry and cell live-dead imaging assay were adopted to characterize the XPC-related drug resistant mechanism. ResultsXPC gene expression was significantly reduced in renal cancer tissue compared with its adjacent tissue. Clinical analysis of TCGA database also identified the downregulated level of XPC gene in renal tumor tissue of stage IV patients with cancer metastasis, which was also correlated with their lower survival rate. 6 natural small-molecules derived from herbal plants including tectorigenin, pinostilbene, d-pinitol, polygalasaponin F, atractylenolide III and astragaloside II significantly enhanced XPC expression in two renal cancer cell types. Combinational treatment of the identified natural compound with the treatment of FDA-approved drug, further confirmed the up-regulation of XPC gene expression can sensitize the two types of XPC-KD drug-resistant renal cancer cells towards the FDA-approved drugs. Mechanistic study confirmed that GSTP1/ROS axis was activated in drug resistant XPC-KD renal cancer cells. ConclusionXPC gene deficiency was identified in patient renal tumor samples, and knockdown of the XPC gene was correlated with a drug-resistant phenotype in renal cancer cells via activation of the GSTP1/ROS axis. The 6 identified natural small molecules were confirmed to have drug sensitizing effects via upregulation of the XPC gene. Therefore, the identified active natural small molecules may work as an adjuvant therapy for circumventing the drug-resistant phenotype in renal cancer via enhancement of XPC expression.

Overcoming multi drug resistance mediated by ABC transporters by a novel acetogenin- annonacin from Annona muricata L.

Ethnopharmacological relevanceMulti-Drug Resistance (MDR), mediated by P-glycoprotein (P-gp) is one of the barriers to successful chemotherapy in colon cancer patients. Annona muricata L. (A.muricata), commonly known as soursop/Graviola, is a medicinal plant that has been traditionally used in treating diverse diseases including cancer. Phytochemicals of A.muricata (Annonaceous Acetogenins-AGEs) have been well-reported for their anti-cancer effects on various cancers. Aim of the studyThe study aimed to examine the effect of AGEs in reversing MDR in colorectal cancer cells. MethodsBased on molecular docking and molecular dynamic simulation, the stability of annonacin upon P-gp was investigated. Further in vitro studies were carried in oxaliplatin-resistant human colon cancer cells (SW480R) to study the biological effect of annonacin, in reversing drug resistance in these cells. ResultsMolecular docking and simulation studies have indicated that annonacin stably interacted at the drug binding site of P-gp. In vitro analysis showed that annonacin was able to significantly reduce the expression of P-gp by 2.56 folds. It also induced apoptosis in the drug-resistant colon cancer cells. Moreover, the intracellular accumulation of P-gp substrate (calcein-AM) was observed to increase in resistant cells upon treatment with annonacin. ConclusionOur findings suggest that annonacin could inhibit the efflux of chemotherapeutic drugs mediated by P-gp and thereby help in reversing MDR in colon cancer cells. Further in vivo studies are required to decipher the underlying mechanism of annonacin in treating MDR cancers.

Anticancer effect of polyphenolic acid enriched fractions from Grewia bracteata Roth on tumor cells and their p53 gene independent ROS mediated apoptosis in colon cancer cells

It is the first report on leaves of Grewia bracteata Roth for its anticancer effect. In this study, three polarity-guided solvent extracts of Grewia bracteata leaves from n-hexane (GLH), ethyl acetate (GLE), and methanol (GLM) were screened for anticancer effects on HeLa, HCT-116, MCF-7, HCT-116 p53−/− and PC-3 cells via methyl thiazoldiphenyltetrazolium bromide (MTT) assay. Based on the results, GLM was fractionated, and the obtained fractions were tested on HCT-116 cells. Further, FT-IR, HPLC analysis, clonogenic assay, wound healing assay, DCFDA, and cell cycle experiments were conducted on HCT-116 cells. The extracts from methanol (GLM) and ethyl-acetate (GLE) demonstrated a more selective and promising inhibition on HCT-116 cells than others. Notably, GLM recorded superior inhibition on HCT-116 p53−/− than GLE. Amongst, the methanol column fraction (GMCF) showed prominent inhibition on HCT-116 (IC50:63.55 ± 0.61 μg/ml) and HCT-116 p53−/− (IC50: 84.51 ± 0.58 μg/ml) cells. Further, the test on normal cells (NKE) revealed minimal toxicity of GMCF. The phytochemical test, FT-IR, HPLC, and LC-HRMS analyses confirmed the high abundance of polyphenolic acid/polyphenols in GMCF. Further, the clonogenic and wound healing assays on HCT-116 cells were also performed. Later, the probable cell death mechanism was identified using DCFDA and cell cycle experiments. These experiments disclosed that GMCF induced HCT-116 cell death was probably due to reactive oxygen species (ROS) upregulation and cells cycle arrest at SubG0 phase. It inferred that the activity is most probably p53 independent, a tumor suppressor gene responsible for drug resistance in colon cancer.

Quercetin reverses 5-fluorouracil resistance in colon cancer cells by modulating the NRF2/HO-1 pathway.

Quercetin (Que) has been proven to enhance the chemosensitivity of multiple cancers, including colon cancer (CC). However, whether the combination of Que and 5-fluorouracil (5-FU) has a synergistic effect on drug-resistant CC cells has not previously been reported. The effect of Que (5 and 10 μg/mL) on cell vitality and apoptosis of CC and CC drug-resistant cells was examined using a cell counting kit-8 (CCK-8) and flow cytometry. After cells were treated with 5-FU (10, 40 μg/mL), Que (10 μM, 40 μM), or 5-FU in combination with Que, cell proliferation, apoptosis, oxidative stress-related factors, reactive oxygen species (ROS), and nuclear factor erythroid 2-related factor (Nrf2)/heme oxygenase-1 (HO-1) pathway-related factors were examined by colony formation assay, flow cytometry, ELISA, ROS kit, immunofluorescence assay, and Western blot. The results showed that 5-FU reduced cell viability and induced apoptosis of CC as well as 5-FU-resistant CC cells. Que further restrained the proliferation, oxidative stress-related factors (SOD, CAT, GPx, and GR), ROS production, and induced apoptosis in CC cells and 5-FU-resistant CC cells induced by 5-FU. Moreover, the combination of Que and 5-FU attenuated the Nrf2/HO-1 pathway-related marker levels in CC cells and 5-FU-resistant CC cells. Therefore, our results suggest that Que reverses 5-FU resistance in CC cells via modulating the Nrf2/HO-1 pathway.

SENP1 decreases RNF168 phase separation to promote DNA damage repair and drug resistance in colon cancer.

The DNA damage response (DDR) is essential for the maintenance of genomic stability. Protein posttranslational modifications play pivotal roles in regulating the DDR process. Here, we found that SUMOylated RNF168 undergoes liquid-liquid phase separation (LLPS), which restricts the recruitment of RNF168 to DNA damage sites, reduces RNF168-catalyzed H2A ubiquitination, restrains 53BP1 in nuclear condensates, and ultimately impairs non-homologous DNA end joining (NHEJ) repair efficiency. SENP1 was identified as a specific deSUMOylase of RNF168, and it was highly expressed in colorectal adenocarcinoma. In response to DNA damage, SENP1 decreased RNF168 SUMOylation and prevented RNF168 from forming nuclear condensates, thus promoting damage repair efficiency and cancer cell resistance to DNA damaging agents. Moreover, high SENP1 expression correlated with poor prognosis in cancer patients, and SENP1 depletion sensitized cancer cells to chemotherapy. In summary, these findings reveal DDR is suppressed by SUMOylation-induced LLPS of RNF168 and suggest that SENP1 is a potential target for cancer therapy.

Targeting microRNA-125b inhibited the metastasis of Alisertib resistance cells through mediating p53 pathway

Objective: To clarify the mechanisms involvement in Alisertib-resistant colorectal cells and explore a potential target to overcome Alisertib-resistance. Methods: Drug-resistant colon cancer cell line (named as HCT-8-7T cells) was established and transplanted into immunodeficient mice. The metastasis in vivo were observed. Proliferation and migration of HCT-8-7T cells and their parental cells were assessed by colony formation and Transwell assay, respectively. Glycolytic capacity and glutamine metabolism of cells were analyzed by metabolism assays. The protein and mRNA levels of critical factors which are involved in mediating glycolysis and epithelial-mesenchymal transition (EMT) were examined by western blot and reverse transcription-quantitative real-time polymerase chain reaction(RT-qPCR), respectively. Results: In comparison with the mice transplanted with HCT-8 cells, which were survival with limited metastatic tumor cells in organs, aggressive metastases were observed in liver, lung, kidney and ovary of HCT-8-7T transplanted mice (P<0.05). The levels of ATP [(0.10±0.01) mmol/L], glycolysis [(81.77±8.21) mpH/min] and the capacity of glycolysis [(55.50±3.48) mpH/min] in HCT-8-7T cells were higher than those of HCT-8 cells [(0.04±0.01) mmol/L, (27.77±2.55) mpH/min and(14.00±1.19) mpH/min, respectively, P<0.05]. Meanwhile, the levels of p53 protein and mRNA in HCT-8-7T cells were potently decreased as compared to that in HCT-8 cells (P<0.05). However, the level of miRNA-125b (2.21±0.12) in HCT-8-7T cells was significantly elevated as compared to that in HCT-8 cells (1.00±0.00, P<0.001). In HCT-8-7T cells, forced-expression of p53 reduced the colon number (162.00±24.00) and the migration [(18.53±5.67)%] as compared with those in cells transfected with control vector [274.70±40.50 and (100.00±29.06)%, P<0.05, respectively]. Similarly, miR-125b mimic decreased the glycolysis [(25.28±9.51) mpH/min] in HCT-8-7T cells as compared with that [(54.38±12.70)mpH/min, P=0.003] in HCT-8-7T cells transfected with control. Meanwhile, in comparison with control transfected HCT-8-7T cells, miR-125b mimic also significantly led to an increase in the levels of p53 and β-catenin, in parallel with a decrease in the levels of PFK1 and HK1 in HCT-8-7T cells (P<0.05). Conclusions: Silencing of p53 by miR-125b could be one of the mechanisms that contributes to Alisertib resistance. Targeting miR-125b could be a strategy to overcome Alisertib resistance.

The involvement of Aurora-A and p53 in oxaliplatin-resistant colon cancer cells.

Resistance to chemotherapy is the deadlock in cancer treatment. In this study, we used wild-type LOVO (LOVOWT ), a human colon cancer cell line, and the oxaliplatin-resistant sub-clone LOVOOR cells to investigate the molecular mechanisms of the development of drug resistance in colon cancer. Compared with LOVOWT cells, LOVOOR cells had a high proliferation capacity and a high percentage on the G2/M phase. The expression and activation of Aurora-A, a critical kinase in G2/M phase, were higher in LOVOOR cells than in LOVOWT cells. The results from immunofluorescence indicated an irregular distribution of Aurora-A in LOVOOR cells. To evaluate the importance of Aurora-A in oxaliplatin-resistant property of LOVOOR cells, overexpression of Aurora-A in LOVOWT cells and otherwise knockdown of Aurora-A in LOVOOR cells were performed and followed by administration of oxaliplatin. The results indicated that Aurora-A might contribute to the resistance of LOVOOR cells to oxaliplatin treatment by depressing p53 signaling. The specific findings in this study provide a possibility that targeting Aurora-A might be a solution for patients who have failed oxaliplatin treatment.

The effect and mechanistic study of encequidar on reversing the resistance of SW620/AD300 cells to doxorubicin

Encequidar, a gut-specific P-glycoprotein (P-gp) inhibitor, makes oral paclitaxel possible, and has been used in clinical treatment of metastatic breast cancer, however, its pharmacological effect and mechanism of reversal of drug resistance in drug-resistant colon cancer cells SW620/AD300 are still unknown. Herein, we first synthesized encequidar and demonstrated that it could inhibit the transport activity of P-gp, reduced doxorubicin (DOX) efflux, enhanced DOX cytotoxicity and promoted tumor-apoptosis in SW620/AD300 cells. Metabolomic analysis of cell samples was performedusing liquid chromatography Q-Exactive mass spectrometer, the results of metabolite enrichment analysis and pathway analysis showed that the combination of encequidar and DOX could: i) significantly affect the citric acid cycle (TCA cycle) and reduce the energy supply required for P-gp to exert its transport activity; ii) affect the metabolism of glutathione, which is the main component of the anti-oxidative stress system, and reduce the ability of cells to resist oxidative stress; iii) increase the intracellular reactive oxygen species (ROS) production and enhance ROS-induced cell damage and lipid peroxidation, which in turn restore the sensitivity of drug-resistant cells to DOX. In conclusion, these results provide sufficient data support for the therapeutical application of the P-gp inhibitor encequidar to reverse MDR, and are of great significance to further understand the therapeutic advantages of encequidar in anti-tumor therapy and guide clinical rational drug use.

The role of autophagy in the treatment of colon cancer by chlorin e6 photodynamic therapy combined with oxaliplatin

BackgroundPhotodynamic therapy is a tumour treatment method. Its mechanism mainly induces apoptosis, autophagy, and other ways to cause cell death. Therefore, this study aims to evaluate the therapeutic effect of chlorine e6 photodynamic therapy (Ce6-PDT) combined with oxaliplatin (L-OHP) in colon cancer and to investigate the role of autophagy in L-OHP treatment and Ce6-PDT combined with L-OHP in colon cancer. MethodsCCK-8 assay, Scratch wound healing assay, and Western Blot (WB) were used to identify drug-resistant colon cancer cell line SW620/L-OHP. Annexin V/FITC assay, laser confocal double immunofluorescence staining method and WB were employed to investigate the apoptosis and autophagy changes in Ce6-PDT combined with L-OHP. ResultsDrug resistance cells SW620/L-OHP were developed under the continuous multi-generation of L-OHP treatment, and the expression of ATP-binding cassette subfamily B member 1 (ABCB1) and ATG5 proteins were increased. The results of immunofluorescence showed that LC3B accumulated in SW620 cells and SW620/L-OHP cells under the treatment of L-OHP. The WB results indicated that LC3B and ATG5 protein expression was increasing in SW620 cells and SW620/L-OHP cells. Inhibition of L-OHP-induced autophagy reduces SW620 cells and SW620/L-OHP cells’ viability while increasing apoptosis and the Pro Caspase-3 protein expression. The combination of Ce6-PDT and L-OHP decreased the cell viability, the cell migration ability, the Bcl-2 protein expression, and increased the apoptosis rate, Pro Caspase-3 protein expression in SW620 cells. ConclusionsL-OHP can cause SW620 cells drug resistance. Autophagy plays a protective role in the L-OHP treatment of SW620 cells and SW620/L-OHP cells, and inhibition of autophagy can increase the efficacy of L-OHP. Ce6-PDT combined with L-OHP can further improve the tumor's therapeutic effect, and autophagy inhibition can improve the efficacy of combined therapy.

The Activation of the Tumor Suppressor Protein p53 by Acriflavine Leads to Mitochondrial Dysfunction and Improves the Radiosensitivity of Colon Cancer Cells.

Colon cancer ranks third worldwide, and it has a growing incidence with urbanization and industrialization. Drug resistance in colon cancer is gradually affecting the treatment. This study focused on the mechanisms by which acriflavine (ACF) enhances the radiosensitivity of colon cancer cells. First, the expression and activation levels of tumor suppressor protein p53 were shown high in normal cells and tissues in its detection, which suggests that p53 is likely to be a key factor in colon cancer. Then, the expression of p53 ended up increasing in ACF group after SW620 cells were cultured with ACF. In addition, ACF group had some other changes. The expression of mitochondrial related antiapoptotic protein Bcl-2 increased, while the expression of proapoptotic protein Bax, Bad, cytopigment C, and apoptotic inducer AIF decreased. At the same time, the ability of apoptosis was enhanced, and the ability of proliferation and invasion was decreased. This suggests that ACF can promote p53 expression and affect mitochondrial function and the radiosensitivity of SW620. The luciferase reporting experiment showed that there was a binding site between ACF and p53. Besides, when IR treatment was applied to SW620 with high p53 expression, there was an increase in the expression of Bcl-2 in SW620 and decrease in Bax, Bad, and cytopigment C in AIF. Meanwhile, the cell apoptosis became stronger, and the proliferation and invasion became weaker. The experimental results were similar to those of SW620 cells cultured with ACF, suggesting that p53 is an intermediate factor in the regulation of SW620 by ACF. Finally, in this study, cells were cultured with ACF, and p53 was knocked down at the same time. The experimental results showed that after p53 was knocked down. ACF's ability to regulate SW620 is partially removed. This confirms the view that ACF regulates SW620 cells by regulating p53. In summary, this study found the mechanism by which ACF causes mitochondrial dysfunction and improves the radiosensitivity of colon cancer cells by activating the tumor suppressor protein p53, which may contribute to solving the drug resistance in colon cancer.

Expression of Long Nonencoding Ribonucleic Acid SNHG20 in Colon Cancer Tissue in Its Influences on Chemotherapeutic Sensitivity of Colon Cancer Cells.

Noncoding RNA (ncRNA) is a kind of RNA that plays a key role in a variety of biological processes, illnesses, and tumours despite the fact that it cannot be translated into proteins. The HT29 colon cancer cell line was utilized to create a 5-FU drug-resistant cell strain (control group), a lentivirus SNHG20 carrier (OE-SNHG20 group), and an SNHG20 shRNA carrier (SNHG20 shRNA carrier group) (SE-SNHG20 group). To determine the expression of cell SNHG20, a real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR) was utilized, and cholecystokinin-octapeptide (CCK-8) was used to detect the difference in 5-FU inhibitory concentration 50. The goal of the study was to see how variations in long nonencoding ribonucleic acid (lncRNA) SNHG20 expression affect colon cancer cell 5-fluorouracil (5-FU) chemotherapeutic sensitivity by collecting colon cancer and normal para cancer tissues and analysing the differences in SNHG20 expression. The ability of cell cladogenesis was tested using platform cladogenesis. Cell apoptosis was detected using flow cytometry. Western blots revealed the presence of protein phosphatidylinositol kinase (PI3K), protein kinase B (AKT), caspase-3, e-cadherin, and matrix metalloproteinase 9 (MMP-9) enzymes. The findings revealed that SNHG20 expression was considerably upregulated (P < 0.05) in colon cancer tissue and 5-FU drug-resistant colon cancer cells. Cell 5-FU IC50, cell cladogenesis, cell survival rate, and MMP-9, P-PI3K, and P-AKT expression were all significantly improved. Cell apoptosis and expressions of E-cadherin and caspase-3, on the other hand, were considerably decreased (P < 0.05). Cell 5-FU IC50, cell cladogenesis, cell survival rate, and the expressions of MMP-9, P-PI3K, and P-AKT were all significantly lower in the SE-SNHG20 group, although cell apoptosis and the expressions of E-cadherin and caspase-3 were significantly higher (P < 0.05). The results revealed that lncRNA SNHG20 could inhibit the chemotherapeutic sensitivity of colon cancer cells to 5-FU by regulating PI3K/AKT pathways. The inhibition of lncRNA SNHG20 expression could promote the apoptosis and proliferation of 5-FU-resistant colon cancer cells.

AKT inhibition sensitizes EVI1 expressing colon cancer cells to irinotecan therapy by regulating the Akt/mTOR axis.

Ecotropic viral integration site 1 (EVI1) is an oncogenic transcription factor that has been attributed to chemotherapy resistance in different cancers. As yet, however, its role in colon cancer drug resistance is not completely understood. Here, we set out to investigate the functional and therapeutic relevance of EVI1 in colon cancer drug resistance. The EVI1 gene was knocked down in colon cancer cells that were subsequently tested for susceptibility to irinotecan using in vitro assays and in vivo subcutaneous mouse colon cancer models. The effect of EVI1 knockdown on the AKT-mTOR signaling pathway was assessed using cell line models, immunohistochemistry and bioinformatics tools. The anti-proliferative activity of AKT inhibitor GSK690693 and its combination with irinotecan was tested in colon cancer cell line models (2D and 3D). Finally, the therapeutic efficacy of GSK690693 and its combination with irinotecan was evaluated in xenografted EVI1 expressing colon cancer mouse models. We found that EVI1 knockdown decreased cancer stem cell-like properties and improved irinotecan responses in both cell line and subcutaneous mouse models. In addition, we found that EVI1 downregulation resulted in inhibition of AKT/mTOR signaling and RICTOR expression. Knocking down RICTOR expression increased the cytotoxic effects of irinotecan in EVI1 downregulated colon cancer cells. Co-treatment with irinotecan and ATP-competitive AKT inhibitor GSK690693 significantly reduced colon cancer cell survival and tumor progression rates. Inhibition of the AKT signaling cascade by GSK690693 may serve as an alternative to improve the irinotecan response in EVI1-expressing colon cancer cells.

Non-Canonical Programmed Cell Death in Colon Cancer.

Simple SummaryNon-canonical PCD is an important player in colon cancer cell suicide. It influences colon cancer in many ways, such as through tumorigenesis, treatment, and prognosis. In this review, we present the mechanism, application, and prospect of different types of non-canonical PCD in colon cancer.Programmed cell death (PCD) is an evolutionarily conserved process of cell suicide that is regulated by various genes and the interaction of multiple signal pathways. Non-canonical programmed cell death (PCD) represents different signaling excluding apoptosis. Colon cancer is the third most incident and the fourth most mortal worldwide. Multiple factors such as alcohol, obesity, and genetic and epigenetic alternations contribute to the carcinogenesis of colon cancer. In recent years, emerging evidence has suggested that diverse types of non-canonical programmed cell death are involved in the initiation and development of colon cancer, including mitotic catastrophe, ferroptosis, pyroptosis, necroptosis, parthanatos, oxeiptosis, NETosis, PANoptosis, and entosis. In this review, we summarized the association of different types of non-canonical PCD with tumorigenesis, progression, prevention, treatments, and prognosis of colon cancer. In addition, the prospect of drug-resistant colon cancer therapy related to non-canonical PCD, and the interaction between different types of non-canonical PCD, was systemically reviewed.

DPEP1 promotes drug resistance in colon cancer cells by forming a positive feedback loop with ASCL2.

Drug resistance is an important factor affecting the efficacy of chemotherapy in patients with colon cancer. However, clinical markers for diagnosing drug resistance of tumor cells are not only a few in number, but also low in specificity, and the mechanism of action of tumor cell drug resistance remains unclear. Dipeptidase 1 (DPEP1) expression was analyzed using the cancer genome atlas (TCGA) and genotype-Tissue Expression pan-cancer data. Survival analysis was performed using the survival package in R software to assess the prognostic value of DPEP1 expression in colon cancer. Correlation and Venn analyses were adopted to identify key genes. Immunohistochemistry, western blot, qRT-PCR, Co-immunoprecipitation, and dual-luciferase reporter experiments were carried out to explore the underlying associations between DPEP1 and Achaete scute-like 2 (ASCL2). MTT assays were used to evaluate the role of DPEP1 and ASCL2 in colon cancer drug resistance. DPEP1 was highly expressed in colon cancer tissues. DPEP1 expression correlated negatively with disease-specific survival but not with overall survival. Bioinformatics analysis and experiments showed that the expressions of DPEP1 and ASCL2 in colon cancer tissues were markedly positively correlated. Mechanistic research indicated that DPEP1 enhanced the stability of protein ASCL2 by inhibiting its ubiquitination-mediated degradation. In turn, ASCL2 functioned as a transcription factor to activate the transcriptional activity of the DPEP1 gene and boost its expression. Furthermore, DPEP1 also could enhance the expression of colon cancer stem cell markers (LGR5, CD133, and CD44), which strengthened the tolerance of colon cancer cells to chemotherapy drugs. Our findings reveal that the DPEP1 enhances the stemness of tumor cells by forming a positive feedback loop with ASCL2 to improve resistance to chemotherapy drugs.

Construction of immune-related lncRNA signature to predict aggressiveness, immune landscape, and drug resistance of colon cancer

BackgroundColon cancer remains one of the most common malignancies across the world. Thus far, a biomarker, which can comprehensively predict the survival outcomes, clinical characteristics, and therapeutic sensitivity, is still lacking.MethodsWe leveraged transcriptomic data of colon cancer from the existing datasets and constructed immune-related lncRNA (irlncRNA) pairs. After integrating with clinical survival data, we performed differential analysis and identified 11 irlncRNAs signature using Lasso regression analysis. We next plotted the 1-, 5-, and 10-year curve lines of receiver operating characteristics, calculated the areas under the curve, and recognized the optimal cutoff point. Then, we validated the pair-risk model in terms of the survival outcomes of the patients involved. Moreover, we tested the reliability of the model for predicting tumor aggressiveness and therapeutic susceptibility of colon cancer. Additionally, we reemployed the 11 of irlncRNAs involved in the pair-risk model to construct an expression-risk model to predict the prognostic outcomes of the patients involved.ResultsWe recognized a total of 377 differentially expressed irlncRNAs (DEirlcRNAs), including 28 low-expressed and 349 high-expressed irlncRNAs in colon cancer patients. After performing a univariant Cox analysis, we identified 115 risk irlncRNAs that were significantly correlated with survival outcomes of patients involved. By taking the overlap of the DEirlcRNAs and the risk irlncRNAs, we ultimately recognized 55 irlncRNAs as core irlncRNAs. Then, we established a Cox HR model (pair-risk model) as well as an expression HR model (exp-risk model) based on 11 of the 55 core irlncRNAs. We found that both of the two models significantly outperformed the commonly used clinical characteristics, including age, T, N, and M stages when predicting survival outcomes. Moreover, we validated the pair-risk model as a potential tool for studying the tumor microenvironment of colon cancer and drug susceptibility. Additionally, we noticed that combinational use of the pair-risk model and the exp-risk model yielded a more robust approach for predicting the survival outcomes of patients with colon cancer.ConclusionsWe recognized 11 irlncRNAs and created a pair-risk model and an exp-risk model, which have the potential to predict clinical characteristics of colon cancer, either solely or conjointly.

MCP mediated active targeting calcium phosphate hybrid nanoparticles for the treatment of orthotopic drug-resistant colon cancer

BackgroundColon cancer is a most common malignant cancer in digestive system, and it is prone to develop resistance to the commonly used chemotherapy drugs, leading to local recurrence and metastasis. Paris saponin VII (PSVII) could not only inhibit the proliferation of colon cancer cells but also effectively induce apoptosis of drug-resistant colon cancer cells and reduce the metastasis of drug-resistant colon cancer cells as well. However, PSVII was insoluble in water and fat. It displayed no selective distribution in body and could cause severe hemolysis. Herein, colon cancer targeting calcium phosphate nanoparticles were developed to carry PSVII to treat drug-resistant colon cancer.ResultsPSVII carboxymethyl-β-cyclodextrin inclusion compound was successfully encapsulated in colon cancer targeting calcium phosphate nanoparticles (PSVII@MCP-CaP) by using modified citrus pectin as stabilizer agent and colon cancer cell targeting moiety. PSVII@MCP-CaP significantly reduced the hemolysis of PSVII. Moreover, by specific accumulating in orthotopic drug-resistant colon cancer tissue, PSVII@MCP-CaP markedly inhibited the growth of orthotopic drug-resistant colon cancer in nude mice. PSVII@MCP-CaP promoted the apoptosis of drug-resistant colon cancer cells through mitochondria-mediated apoptosis pathway. Moreover, PSVII@MCP-CaP significantly inhibited the invasion and migration of drug-resistant colon cancer cells by increasing E-cadherin protein expression and reducing N-cadherin and MMP-9 protein expression.ConclusionPSVII@MCP-CaP has great potential in the treatment of drug-resistant colon cancer. This study also explores a new method to prepare active targeting calcium phosphate nanoparticles loaded with a fat and water insoluble compound in water.Graphical