Colon Cancer Cells Research Articles

DNA interaction and cytotoxicity of a new asymmetric dimer cobalt(II) complex [Co(phen)2(Cl2)]3(H2O).[Co(phen)2(Cl)(H2O)](Cl)

The new, unusual and asymmetric cobalt(II) complex, [Co(phen)2(Cl2)]3(H2O).[Co(phen)2(Cl)(H2O)](Cl) (phen ​= ​1,10-phenanthroline), has been synthesized and characterized structurally by regular spectral and single crystal XRD analysis. An asymmetric complex crystallized in a monoclinic system with space group P21/c, a ​= ​14.093(5) Å, b ​= ​24.089(5) Å, c ​= ​14.241(5) Å, α ​= ​90.000(5)°, β ​= ​98.010(5)°, and γ ​= ​90.000(5)°. DNA binding interactions of complex with calf thymus DNA (CT-DNA) has investigated by UV–Vis absorption, ethidium bromide displacement assay, viscometric and cyclic voltammetric titrations, and the results infer an intercalation mode of binding. Complex cleaves effectively plasmid pBR322 DNA, and exhibits remarkable cytotoxic activity against human colon cancer cell line (HCT15).

Streamlining RNA Aptamer Selection via Unique Molecular Identifiers and High-Throughput Sequencing.

Aptamers are valuable tools for applications such as cell imaging, drug delivery, and therapeutics. RNA aptamers, in particular, exhibit complex structural diversity and flexibility, affording higher affinity and specificity, broader target recognition, and easier chemical modification compared with DNA aptamers. However, traditional selection methods for RNA aptamers are time-consuming and involve numerous rounds of screening, thus limiting their widespread application. To overcome this challenge, we propose an efficient truncated selection approach termed ID-SELEX. This method incorporates a molecular identification marker whereby each template is labeled with a unique molecular identifier, or UMI. Such incorporation helps mitigate biases introduced by multiple polymerase chain reaction (PCR) amplification during high-throughput sequencing, ensuring accurate identification of aptamer candidates. Utilizing ID-SELEX, we successfully identified a panel of high-quality aptamers targeting the human colon cancer cell line HCT-8 in just 2 rounds of selection. Furthermore, we demonstrated the versatility of this strategy by selecting 6 RNA aptamers targeting mouse myoblast cell line C2C12 with only one round of selection. In summary, RNA aptamer selection based on ID-SELEX utilizes high-throughput sequencing and UMI labeling to enable the rapid screening of RNA aptamers across human and murine cell lines. As such, ID-SELEX has the potential to facilitate RNA aptamer discovery, providing a novel molecular tool for biomedical research, clinical applications, and precision medicine.

Riluzole Enhancing anti-PD-1 Efficacy by Activating cGAS/STING Signaling in Colorectal Cancer.

Colorectal cancer is the second leading cause of cancer mortality in the US. Although immune checkpoint blockade therapies including anti-PD-1/PD-L1 have been successful in treating a subset of colorectal cancer patients, response rates remain low. We have found that riluzole, a well-tolerated FDA-approved oral medicine for treating amyotrophic lateral sclerosis, increased intratumoral CD8+ T cells and suppressed tumor growth of colon cancer cells in syngeneic immune competent mice. Riluzole-mediated tumor suppression was dependent on the presence of CD8+ T cells. Riluzole activates the cytosolic DNA sensing cGAS/STING pathway in colon cancer cells, resulting in increased expression of interferon β (IFNβ) and IFNβ-regulated genes including CXCL10. Inhibition of ATM, but not ATR, resulted in a synergistic increase in IFNβ expression, suggesting that riluzole induces ATM-mediated damage response that contribute to cGAS/STING activation. Depletion of cGAS or STING significantly attenuated riluzole-induced expression of IFNβ and CXCL10 as well as increase of intratumoral CD8+ T cells and suppression of tumor growth. These results indicate that riluzole-mediated tumor infiltration of CD8+ T cells and attenuation of tumor growth is dependent on tumor cell intrinsic STING activation. To determine whether riluzole treatment primes the tumor microenvironment for immune checkpoint modulation, riluzole was combined with anti-PD-1 treatment. This combination showed greater efficacy than either single agent, and strongly suppressed tumor growth in vivo. Taken together, our studies indicate that riluzole activates cGAS/STING-mediated innate immune responses, which might be exploited to sensitize colorectal tumors to anti-PD-1/PD-L1 therapies. .

Transglutaminase 2 promotes epithelial-to-mesenchymal transition by regulating the expression of matrix metalloproteinase 7 in colorectal cancer cells via the MEK/ERK signaling pathway

Tissue transglutaminase 2 (TGM2) and matrix metalloproteinase 7 (MMP7) are suggested to be involved in cancer development and progression, however, their specific role in colon cancer remains elusive. The present study investigated whether TGM2 and MMP7 influence epithelial-mesenchymal-transition (EMT) processes of colon cancer cells.TGM2 was either overexpressed or knocked down in SW480 and HCT-116 cells, and MMP7 expression and activity analyzed. Conversely, MMP7 was silenced and its correlation with TGM2 expression and activity examined. Co-immunoprecipitation served to evaluate TGM2-MMP7-interaction. TGM2 and MMP7 expression were correlated with invasion, migration, EMT marker expression (E-cadherin, N-cadherin, Slug, Snail), and ERK/MEK signaling.TGM2 overexpression enhanced MMP7 expression and activity, promoted cell invasion, migration and EMT, characterized by increased N-cadherin and Snail/Slug expression. TGM2 knockdown resulted in the opposite effects. Knocking down MMP7 was associated with reduced TGM2 protein expression, cell invasion and migration. Down-regulation of MMP7 diminished ERK/MEK signaling, whereas its up-regulation activated this pathway. The ERK-inhibitor GDC-0994 blocked phosphorylation of MEK/ERK and suppressed TGM2 and MMP7.TGM2 communicates with MMP7 in colon cancer cells forces cell migration and invasion by the MEK/ERK signaling pathway and triggers EMT. Inhibiting TGM2 could thus offer new therapeutic options to treat patients with colon cancer, particularly to prevent metastatic progression.

Pentathiepins are an understudied molecular prism of biological activities.

The pentathiepin core was first synthesized in 1971, and while synthetic techniques have progressed over subsequent decades, the biological applications of this heterocycle have received less attention and are only now becoming more apparent. The first natural product, varacin, was identified in 1991, showing cytotoxicity toward a human colon cancer cell line. More recently, the pentathiepin has acted as a surrogate to replace elemental sulfur, that was discovered as a hit in neurodegenerative animal models. A variety of other medicinal chemistryapplications have recently been disclosed. Here, we summarize these indications and highlight the main synthetic pathways to access the pentathiepin core. We offer a concise summary and future perspective of this unique sulfur isosteric replacement.

Exploring health beneficial effects of poisonous mushroom Paxillus involutus Batsch Fr.

In the present study, phenolic and flavonoid composition and biological properties of methanolic extract of wild growing Paxillus involutus collected in Serbia have been investigated. Ellagic acid was the most abundant phenolic compound (34.92 µg g−1), followed by 5-O-caffeoylquinic acid (4.51 µg g−1), whereas isoorientin was the most abundant flavonoid (3.42 µg g−1). P. involutus turned out to be a rich source of phenolic compounds (74.67 mg GAE g−1 d.w.), whereas total flavonoid content was significantly lower (4.05 mg QE g−1 d.w.). As for the various investigated biological activities, methanolic extract exerted high level of antioxidant, antimicrobial and antibiofilm activities. The highest antioxidative potential was measured by TAC (350 TE mg g−1 d.w.), whereas evaluation of antimicrobial properties showed selective antimicrobial potential toward tested pathogenic microorganisms, with resistant strain of E. coli being the most susceptible to the activity of the extract (MIC 0.08 mg mL−1, MBC 0.16 mg mL−1). Furthermore, methanolic extract of P. involutus demonstrated genotoxicity, severe hemolysis effects and selective cytotoxicity against colon cancer cells. From the obtained data, it may be concluded that investigated mushroom albeit being toxic for human consumption, may be considered as a source of highly bioactive components with potential application in drug development.

The medicinal plants effects on the gene expression of cytochrome P450 and P-glycoprotein in cultured colon and breast cancer cell line

The medicinal plants effects on the gene expression of cytochrome P450 and P-glycoprotein in cultured colon and breast cancer cell line

Targeted delivery of oxaliplatin to colorectal cancer using the cancer-specific cell-penetrating peptide BR2

Oxaliplatin is one of the main drugs used in chemotherapy to treat advanced colorectal cancer (CRC), but its effectiveness is limited by its weak cellular uptake, and poor targeting to cancer cells, which can lead to drug resistance and adverse effects in patients. To address these issues, we tested a cell-penetrating, cancer-specific peptide called BR2 as a new peptide-drug conjugate. We conjugated oxaliplatin with BR2 covalently using a heterobifunctional linker. The resulting conjugate (BR2-Oxal) was examined for in vitro and in vivo effectiveness against human colon cancer cells and tumors. Compared with the parent drug, the in vitro investigations showed selective cellular uptake of BR2-Oxal in cancer cells rather than in normal cells and a significantly greater reduction in colon cancer cell viability due to a higher ratio of apoptosis. We also found that BR2-Oxal exhibited a higher accumulation in tumors and greater tumor suppression than oxaliplatin in a xenograft mouse model, suggesting that BR2-Oxal was efficiently and specifically delivered to tumors in vivo. These findings indicate that using the BR2 peptide for the intracellular delivery of oxaliplatin is a promising drug-delivery strategy. This approach also has the potential to enhance the efficiency of oxaliplatin prodrugs or derivatives.

Antibacterial Peptide Nisin Activates p53 Gene Expression and Triggers Apoptosis in Human Colon Cancer Cells

ABSTRACTAntimicrobial peptides (AMPs) are renowned for their broad‐spectrum efficacy against viruses, bacteria, and fungi, thereby holding promise for medicinal applications. Nisin, a bacteriocin synthesized by gram‐positive bacteria such as Lactobacillus and Streptococcus, has been used as a food preservative owing to its antimicrobial characteristics for decades. However, recent developments prompt further research on its application as therapeutic interventions, mainly focusing on anticancer activity. In line with this, the present study portrays the effects of nisin on human colorectal cancer cells and the underlying molecular mechanisms. A dose‐dependent decrease in cell viability with increasing concentrations of nisin was determined by the Alamar blue viability assay, which was supported by significant morphological changes in cells. Subsequently, we probed the apoptotic effects of nisin using EtBr/AO staining, confirming the induction of apoptosis upon nisin treatment, which was further confirmed by ELISA analysis. Elevated levels of Caspase 7 indicated increased apoptosis in nisin‐treated cells. As pharmaceutical p53 reactivation is considered as an attractive strategy to combat chemoresistance and adverse effects, the effect of nisin on p53 expression was determined by mRNA analysis. An upregulation in p53 expression in nisin‐treated cells compared to untreated controls suggests that bacterial nisin reactivates mutated p53. To assess cell cycle dynamics, we utilized PI flow cytometry, unveiling a G0/G1 phase arrest in nisin‐treated cells in contrast to untreated controls. In summary, our results strongly advocate the potential of nisin as a compelling candidate for drug development against colorectal cancer.

Investigating the antioxidant properties and GC-MS profile of Indian native medicinal flower Pandanus odorifer and assessing its cytotoxic effects on HT-29 cells

This study aimed to investigate the antioxidant potential and bioactive compounds of Pandanus odorifer flower. The phytochemical investigation includes both qualitative and quantitative experiments. In vitro antioxidant studies were conducted using DPPH, ABTS and hydroxyl methods. The bioactive compounds present in the ethanol extract were identified using GC-MS analysis. The MTT assay was carried out on HT-29 colon cancer cells to investigate the cytotoxic ability of the ethanolic extract. The qualitative phytochemical analysis demonstrated the presence of flavonoids, phenolic compounds, tannins, saponins, steroids, carboxylic acids and cardiac glycosides. The determination of flavonoid showed 400 ± 0.110 mg/g and 250±0.090 mg/g of quercetin equivalent in ethanol and water extracts. Similarly, the determination of phenol exhibited 108±0.210 mg/g and 87±0.173 mg/g gallic acid equivalent in ethanol and water extracts. The total antioxidant capacity revealed 1.6 ± 0.093 mg/g and 1.3± 0.056 mg/g equivalent of ascorbic acid in ethanol and water extracts. The DPPH assay showed IC50 values of 35.06 µg/mL in ethanol and 44.82 µg/mL in water extract. Likewise, the ABTS assay revealed an IC50 value of 42.20 µg/mL and 47.45 µg/mL in ethanol and water extract. The hydroxyl radical assay showed IC50 value of 23.95 µg/mL in ethanol and 36.56 µg/mL in water extract. 22 bioactive compounds were identified using GC-MS analysis based on their similarity index. The ethanolic extract showed greater cytotoxic activity with the IC50 value of 28.08 µg/mL on HT-29 colon cancer cells. This study concludes that the Pandanus odorifer flower extracts exhibited significant antioxidant and cytotoxic property.

Modulatory Effects of Chalcone Thio-Derivatives on NF-κB and STAT3 Signaling Pathways in Hepatocellular Carcinoma Cells: A Study on Selected Active Compounds.

Our previous studies demonstrated the modulatory effects of new synthetic thio-chalcone derivatives in dishes on the Nrf2, NF-κB, and STAT3 signaling pathways in colon cancer cells. This study aimed to evaluate the effect of four selected active chalcone thio-derivatives on the NF-κB and STAT3 signaling pathways involved in inflammatory processes and cell proliferation in human liver cancer cells. Cell survival was assessed for cancer (HepG2) and normal (THLE-2) cell lines. Activation of NF-κB and STAT3 signaling pathways and the expression of proteins controlled by these pathways were estimated by Western blot, and qRT-PCR assessed the expression of NF-κB and STAT3 target genes. We also evaluated the impact on the selected kinases responsible for the phosphorylation of the studied transcription factors by MagneticBead-Based Multiplex Immunoassay. Among the thio-derivatives tested, especially derivatives 1 and 5, there was an impact on cell viability, cell cycle, apoptosis, and activation of NF-κB and STAT3 pathways in hepatocellular carcinoma (HCC), which confirms the possibilities of using them in combinatorial molecular targeted therapy of HCC. The tested synthetic thio-chalcones exhibit anticancer activity by initiating proapoptotic processes in HCC while showing low toxicity to non-cancerous cells. These findings confirm the possibility of using chalcone thio-derivatives in molecularly targeted combination therapy for HCC.

One-pot biocatalysis of potato rhamnogalacturonan and the role of its deacetylation in efficient inhibition of colon cancer cells and hydrogel mediated colon-targeted drug delivery

Deacetylation of potato rhamnogalacturonan (PRG) by rhamnogalacturonan acetyl esterase (CtPae12B) was explored for enhanced hydrolysis of PRG by rhamnogalacturonan lyase (CtRGLf) and the effects of deacetylated PRG were studied in enhancing inhibition of colon-cancer cells and formation of colon-targeting drug delivery material. Pre-treatment of PRG with CtPae12B resulted in increased relative activity of CtRGLf. CtPae12B removed acetyl groups from both O-2 and O-3 positions of D-galactopyranosyluronic acid residues of PRG, resulting in 98 % deacetylation. PRG displayed 21.9 % degree of acetylation and 7.7 % degree of methylation. TLC and ESI-MS analysis of CtRGLf hydrolysed PRG showed unsaturated RG di-saccharide as the smallest product, with m/z 322. Deacetylated PRG-oligosaccharides displayed higher, 50 % inhibition of colon-cancer HCT-116 cells (with shrunken and globular morphology) than 35 % inhibition by acetylated PRG-oligosaccharides. FESEM and BET analysis of CtPae12B-treated PRG showed porous structure and significantly higher total surface area and pore volume than non-enzyme treated PRG. Higher drug entrapment efficiency and lower drug release rate of CtPae12B-treated PRG hydrogel (0.0033 min−1 at pH 1.2 and 0.009 min−1 at pH 7.4), than non-enzyme treated PRG hydrogel, (0.0057 min−1 at pH 1.2 and 0.02 min−1 at pH 7.4), showed it to be a potential biomaterial for sustainable colon-targeted drug delivery.

IL-4 Downregulates PD-L1 Level Via SOCS1 Upregulation-Induced JNK Deactivation to Enhance Antitumor Immunity in In Vitro Colorectal Cancer.

Interleukin-4 (IL-4) controls cell growth and immune system regulation in tumorigenesis and can inhibit the growth of colon cancer cell lines, but the possible mechanism is unclear. In this study, we investigated the possible mechanism of IL-4 in colorectal cancer (CRC) through in vitro experiments. CRC cells received treatment with IL-4 (50 ng/mL), investigating the suppressor of cytokine signaling 1 (SOCS1)-related mechanism underlying the role of IL-4 in the progression and immunosuppression of CRC. The malignant processes of CRC cells and CD8+T cell-mediated immune response in CRC cells were determined by CCK-8, Transwell, wound healing, and flow cytometry assays. Programmed death ligand 1 (PD-L1), SOCS1 expressions, and c-Jun N-terminal kinase (JNK) activation in CRC cells were analyzed by quantitative reverse transcription polymerase chain reaction and/or Western blot. IL-4 repressed the malignant processes, yet promoted the apoptosis of CRC cells. Besides, IL-4 downregulated PD-L1 level, upregulated SOCS1 level, and restrained JNK activation in CRC cells, while enhancing CRC cell-killing effect of CD8+T cells. IL-4-induced effects on the aforementioned malignant processes of CRC cells and the killing effect of CD8+T cells toward CRC cells were all reversed when SOCS1 was knocked down in the CRC cells. IL-4 downregulates PD-L1 level via SOCS1 upregulation-induced JNK deactivation to enhance antitumor immunity in in vitro CRC. The study provides a theoretical basis for the clinical application of IL-4 in antitumor immunity in CRC.

Cowpea bean β-vignin-derived AQQSY peptide exerts an anticancer effect by inducing cell cycle arrest in the G0/G1 phase and modulating apoptotic signals

The anticancer effect of digested β-vignin and pure peptides from cowpea beans was investigated in cultivated human colon cancer cells. The effect of AQQSY on the cell cycle was similar to that of palbociclib, suggesting that AQQSY may function as a CDK-6-targeting agent. AQQSY peptide reduced the p-Rb/Rb ratio and induced apoptosis through an increase of Bax/Bcl-2 ratio, a decrease of XIAP, and activation of caspase-3. VIPASY peptide showed the potential to induce apoptosis through an increase in Bax/Bcl-2 ratio. The combination of VIPASY and AQQSY with palbociclib caused an additive effect on cell inhibition. Treatment with selected peptides from β-vignin digest caused cell cycle arrest by upregulation of p16 and apoptosis by increasing Bax/Bcl-2 ratio and caspase-8. The peptides and β-vignin digest treatments were more selective for cancer cells than the drugs. Additional research is necessary in vivo to understand the mechanisms of cowpea β-vignin-derived peptides in CRC treatment.

B-357 Siemens CA 72-4: an assay for measurement of Tumor Associated Glycoprotein (TAG) 72

Abstract Background The tumor associated glycoprotein (TAG) 72, also known as CA 72-4 is a mucin protein of high molecular weight. CA 72-4 is found on the surface of many cancer cells, including stomach (gastric), ovary, breast, colon and pancreatic cells. CA 72-4 is currently one of the primary markers for the diagnosis of gastric cancer and monitoring the course and efficacy of gastric cancer. In ovarian cancer, it has a higher sensitivity for mucin- type ovarian cancer, and its combination with CA125 for detection can significantly improve the clinical sensitivity. In colorectal cancer, CA 72-4 combined with CEA detection was also found to significantly improve the sensitivity of the initial diagnosis. An assay for CA 72-4 on Siemens Atellica IM (Siemens CA 72-4) is being developed and analytical performance is being presented. Methods The Siemens CA 72-4 assay (in development) is a one-step chemiluminescent microparticle immunoassay (CMIA) for the quantitative determination of CA 72-4 in human serum and plasma. The specimen is incubated with paramagnetic microparticles coated with the monoclonal antibody (mAb) B72.3 and acridinium-labeled mAb CC49 conjugate on the Siemens Atellica IM® System. After incubation and washing, Acid and Base reagents are added. The resulting relative light units (RLUs) are directly proportional to the amount of CA 72-4 in the sample allowing for the quantitative determination of CA 72-4 in the specimen. Results The following performance were determined using 3 unique lots of reagents and calibrators with the calibration range for the assay being 0.00 to 200.00 U/mL. The limit of blank (LoB), limit of detection (LoD), and limit of quantitation at 20% CV (LoQ) were determined and met the goal of ≤ 1.00 U/mL. Linearity according to CLSI EP06 Ed2 was demonstrated for a range of 1.00 through 200.00 U/mL. A Precision study of 2 controls and 5 panels spanning the range of the assay demonstrated a total %CV ≤ 6% for samples ≥ 5.00 U/mL and ≤ 0.25 SD for samples <5.00 U/mL. In the sample tube type study, a matrix comparison of 23 matched serum and plasma samples were evaluated. Passing-Bablock slopes of < 8% and r > 0.99 were observed when evaluating samples within the measurement range for plasma (LiHep, LiHep separator, K2EDTA and K3EDTA) tubes and serum separator tubes (SST) compared to the Red Top serum samples. Five endogenous substances were evaluated for interference in the CA 72-4 assay. The average percent difference between test and control samples for all endogenous interferents was < 10%. Percent difference in the presence of 28 potentially interfering drugs was ≤ 4.0%. Conclusions The Siemens CA 72-4 assay currently in development is a sensitive and precise assay for the quantitative determination of CA 72-4 in human serum and plasma.

RNA transcription assisted universal CRISPR/Cas12a system for programmable analysis of multiple colorectal cancer-associated microRNAs

Accurate analysis of multiple microRNA (miRNA) levels is significantly valuable for early diagnosis of colorectal cancer noninvasively considering the miRNA expression is highly relevant to the occurrence and progression of cancer. However, the low abundance and high sequence homology of miRNAs make their precise determination extremely challenging. Here, we developed a universal and programmable diagnostic strategy allowing for analyzing multiple colorectal cancer-associated miRNAs. The system combined sequentially programmable rolling circle transcription (RCT) and the CRISPR/Cas12a system with high trans-cleavage activity to achieve highly sensitive and specific detection of four target miRNAs. Owing to the remarkable performance of universal RCT-Cas12a strategy, this biosensor could detect miR-21, miR-17, miR-31 and miR-92a with a LOD of 2.1, 1.6, 3.7 and 1.0 pM, respectively. This strategy had a unique advantage in distinguishing human normal colon epithelial cells lines (NCM460) from human colon cancer cells (HT29). In particular, the designed system exhibited superior analytical capability in distinguishing paracancerous and colorectal cancer tissues from patients undergoing colorectal cancer surgery. This arbitrarily programmable, scalable, fast and specific strategy potentially offered an attractive alternative to handle varied challenges encountered with CRISPR-based systems, and held immense promise in scientific research and clinical applications.

Activating transcription factor 4 plays a major role in shaping the transcriptional response to isoginkgetin in HCT116 cells

Activating transcription factor 4 (ATF4) plays a central role in the integrated stress response (ISR) and one overlapping branch of the unfolded protein response (UPR). We recently reported that the splicing inhibitor isoginkgetin (IGG) induced ATF4 protein along with several known ATF4-regulated transcripts in a response that resembled the ISR and UPR. However, the contribution of ATF4-dependent and -independent transcriptional responses to IGG exposure was not known. Here we used RNA-sequencing in HCT116 colon cancer cells and an isogenic subline lacking ATF4 to investigate the contribution of ATF4 to IGG-induced changes in gene expression. Approximately 85% of the IGG-responsive DEGs in HCT116 cells were also differentially expressed in response to the ER stressor thapsigargin (Tg) and these were enriched for genes associated with the UPR and ISR. Most of these were positively regulated by IGG with impaired responses in the ATF4-deficient cells. Nonetheless, there were DEGs that responded similarly in both cell lines. The ATF4-independent IGG-induced DEGs included several metal responsive transcripts encoding metallothionines and a zinc transporter. Taken together, the predominant IGG response was ATF4-dependent in these cells and resembled the UPR and ISR while a second less prominent response involved the ATF4-independent regulation of metal responsive mRNAs.

Potential Oncogenic and Immunosuppressive Roles of Multiple EGF-Like Domains 6 (MEGF6) in Colon Cancer: Insights from Bioinformatic Analysis

Multiple epidermal growth factor-like domains protein 6 (MEGF6) is a high molecular weight protein with several EGF-like domains. Although it has been demonstrated to promote metastasis and chemoresistance in colon cancer cells, its specific oncogenic and immunologic functions remain largely unexplored. This study aims to comprehensively analyze publicly available datasets to define the role of MEGF6 in colon cancer development and immune response modulation. The expression of MEGF6 in colon adenocarcinoma (COAD) and normal tissues at both mRNA and protein levels was assessed using the GEPIA2 and HPA databases, respectively. The UALCAN database was employed to examine the association between MEGF6 expression and clinicopathological outcomes in COAD patients, and survival analysis was conducted using the KM plotter database. Functional enrichment analysis of MEGF6-correlated genes was performed using the ShinyGO online tool. Additionally, the correlation of MEGF6 with immune cell infiltration and immunosuppressive molecules was explored through the TIMER and TISIDB databases. Our analysis revealed significantly higher mRNA and protein expressions of MEGF6 in COAD tissues compared to normal tissues, with associations to cancer stage, nodal metastasis status, and histological subtype. High MEGF6 expression was correlated with poorer survival outcomes, and genes correlated with MEGF6 were enriched in biological processes related to cellular component organization, cell adhesion, and extracellular matrix interaction. Furthermore, MEGF6 expression demonstrated a significant correlation with immune cell infiltration and the expression of immunosuppressive molecules, particularly CTLA-4, PD-1, PD-L1, TGF-β, and IL-10. In conclusion, our findings suggest that MEGF6 may play an oncogenic role by influencing cell and extracellular matrix interactions. Its overexpression may indicate immunosuppressive properties within the cancer microenvironment. Therefore, MEGF6 holds promise as a potential biomarker for predicting both prognosis and therapeutic responses in colon cancer. HIGHLIGHTS MEGF6 has been shown to involve colon cancer growth and chemotherapeutic resistance. Bioinformatics confirmed a prognostic significance of MEGF6 in colon cancer. MEGF6 may exert its oncogenic effects by influencing cell-matrix interactions. MEGF6 expression is correlated with immunosuppressive properties of cancers. GRAPHICAL ABSTRACT

Downregulation of aquaporins and PI3K/AKT and upregulation of PTEN expression induced by the flavone scutellarein in human colon cancer cell lines

Scutellarein has an anticancer potential, but the pathway of its action has not been elucidated. This study investigated scutellarein efficacy against human colorectal cancer (CRC) and explored the possible pathway of its action. MTT assay was employed to detect scutellarein effect on HT-29, SW-480, and HCT116 cells viability. Scutellarein impact on programmed cell death was studied by Annexin V-FITC/PI and its role on migration and invasion was detected by wound healing and transwell chambers. Aquaporin (AQP) 1, 3, and 5 expression before and after scutellarein treatment was approached by quantitative polymerase chain reaction (RT‒qPCR) and immunostaining while Western blotting was used to explore scutellarein effect on PI3K/AKT pathway. Scutellarein induced apoptosis and necrosis in CRC cells, thus inhibiting proliferation, migration, and invasion. Colon cancer cells exhibited positive staining for AQP 1, 3, and 5 which was downregulated by scutellarein. PI3K/AKT pathway mediating cell proliferation and growth was also modulated by scutellarein; phosphatase and tensin (PTEN) was upregulated, whereas PI3K, AKT, and p-AKT expressions were downregulated, and the downstream mTOR and phosphorylated mTOR were also suppressed at the protein level. Data indicated that scutellarein suppressed growth, migration as well as invasion of these CRC cells by downregulating the expression of AQP 1, 3, and 5 and upregulating PTEN where the latter inhibited the genes and the proteins involved in PI3K/AKT pathway. The data indicate that scutellarein is a promising therapeutic agent that inhibits growth, migration, and invasion of CRC cells by down-regulating the expression of AQP 1, 3, and 5 and by PTEN up-regulation, thus inhibiting PI3K/AKT. These molecular alterations represent potential prognostic biomarkers for the metastasis of colon cancer, where the down-regulation of AQPs enhances patient survival.

HMGB2-induced calreticulin translocation required for immunogenic cell death and ferroptosis of cancer cells are controlled by the nuclear exporter XPO1

Cisplatin and oxaliplatin cause the secretion of high mobility group box 1 (HMGB1) protein from cancer cells, which is necessary for initiation of immunogenic cell death (ICD). Calreticulin (CRT) translocation from the endoplasmic reticulum to the plasma membrane is also required; oxaliplatin induces this translocation but cisplatin does not. We have discovered that oxaliplatin causes the secretion of both HMGB1 and HMGB2 from the cell nucleus into the extracellular milieu. We previously showed that cisplatin-mediated secretion of HMGB1 is controlled by the nuclear exporter XPO1 (chromosomal maintenance 1; CRM1). We now find that XPO1 regulates oxaliplatin-mediated secretion of both HMGB1 and HMGB2. XPO1 inhibition causes nuclear accumulation of both proteins, inhibition of oxaliplatin-mediated ferroptosis of colon cancer cells, and inhibition of CRT translocation to the plasma membrane of lung and colon cancer cells. Incubation of cancer cells with cell targeted (CT)-HMGB2 confirmed that HMGB2 is required for the CRT translocation. Furthermore, CT-HMGB2 is three orders of magnitude more potent at inducing CRT translocation than oxaliplatin.