Human Colorectal Carcinoma Research Articles

Promising Effects of Casearins in Tumor-Bearing Mice and Antinociceptive Action against Oncologic Pain: Molecular Docking and In Vivo Findings.

Safer analgesic drugs remain a hard challenge because of cardiovascular and/or gastrointestinal toxicity, mainly. So, this study evaluated in vivo the antiproliferative actions of a fraction with casearins (FC) from Casearia sylvestris leaves against human colorectal carcinomas and antihyperalgesic effects on inflammatory- or opiate-based pain relief and oncologic pain in Sarcoma 180 (S180)-bearing mice. Moreover, docking investigations evaluated the binding among Casearin X and NMDA(N-methyl-D-aspartate)-type glutamate receptors. HCT-116 colorectal carcinoma-xenografted mice were treated with FC for 15 days. Antinociceptive assays included chemically induced algesia and investigated mechanisms by pharmacological blockade. Intraplantar region S180-bearing animals received a single dose of FC and were examined for mechanical allodynia and behavior alterations. AutoDock Vina determined molecular interactions among Cas X and NMDA receptor subunits. FC reduced tumor growth at i.p. (5 and 10 mg/kg) and oral (25 mg/kg/day) doses (31.12-39.27%). FC reduced abdominal pain, as confirmed by formalin and glutamate protocols, whose antinociception activity was blocked by naloxone and L-NAME (neurogenic phase) and naloxone, atropine, and flumazenil (inflammatory phase). Meanwhile, glibenclamide potentiated the FC analgesic effects. FC increased the paw withdrawal threshold without producing changes in exploratory parameters or motor coordination. Cas X generated a more stable complex with active sites of the NMDA receptor GluN2B subunits. FC is a promising antitumor agent against colorectal carcinomas, has peripheral analgesic effects by desensitizing secondary afferent neurons, and inhibits glutamate release from presynaptic neurons and/or their action on cognate receptors. These findings emphasize the use of clerodane diterpenes against cancer-related pain conditions.

Inhibition of Human Colorectal Cancer by a Natural Product 7-Acetylhorminone and Interactions with BSA/HSA: Multispectral Analysis and In Silico and In Vitro Studies.

We have semi-synthesized a natural product 7-acetylhorminone from crude extract of Premna obtusifolia (Indian headache tree), which is active against colorectal cancer after probation through computational screening methods as it passed through the set parameters of pharmacokinetics (most important nonblood-brain barrier permeant) and drug likeliness (e.g., Lipinski's, Ghose's, Veber's rule) which most other phytoconstituents failed to pass combined with docking with EGFR protein which is highly upregulated in the colorectal carcinoma cell. The structure of 7-acetylhorminone was confirmed by single crystal X-ray diffraction studies and 1H NMR, 13C NMR, and COSY studies. To validate the theoretical studies, first, in vitro experiments were carried out against human colorectal carcinoma cell lines (HCT116) which revealed the potent cytotoxic efficacy of 7-acetylhorminone and verified preliminary investigation. Second, the drugability of 7-acetylhorminone interaction with serum albumin proteins (HSA and BSA) is evaluated both theoretically and experimentally via steady-state fluorescence spectroscopic studies, circular dichroism, isothermal titration calorimetry, and molecular docking. In summary, this study reveals the applicability of 7-acetylhorminone as a potent drug candidate or as a combinatorial drug against colorectal cancer.

A Promising Therapeutic Scaffold Fusing Chalcone/Coumarin Targeting Colorectal Cancer: Design, Synthesis, Biological and ADME‐tox Modelling

AbstractEight novel compounds incorporating chalcone and coumarin features, namely chalcone‐coumarin‐ hybrid molecules, were designed, synthetized, and evaluated for their activity against human colorectal carcinoma SW480 cell line. According to the results observed, the hybrid with a 2,3‐dimetoxysubstitution pattern displayed the highest activity at the conditions evaluated, with an IC50 value of 25.18±1.12 μM, being even more active than the reference drug (5‐fluorouracil) and the parental compound (7‐methylcoumarin). In addition, this hybrid compound exhibited significant antiproliferative activity in a time‐ and concentration dependent way, suggesting rather a cytostatic or cytotoxic effect. Moreover, a theoretical drug‐like/pharmacokinetics/toxicological study suggested that the most promising hybrid would have a great chance to advance to further preclinical studies as anti‐cancer therapeutic candidate for oral oncological management. Our study evidently identified the potency of chalcone‐coumarin conjugates, particularly the 2,3‐dimetoxysubstituited molecule to be a prototype drug for further investigations toward novel therapeutics treatments of colorectal cancer.

Structure-Activity Relationship Study of Biselyngbyolide B Reveals Mitochondrial Fission-Induced Cytotoxicity in Cancer.

A systematic structure-activity relationship study of the potent anticancer marine macrolide biselyngbyolide B has been accomplished. A total of 11 structural variants of the parent natural product, of which 2 are natural analogues, have been studied against a human colorectal carcinoma cell line. The requisite functional units of the parent molecule responsible for the cytotoxic activities have been disclosed. Biselyngbyolide C, one of the natural analogues of biselyngbyolide B, has been studied in depth to explore its molecular mechanism. Interestingly, the in vitro data demonstrated an induction of dynamin-related protein 1-mediated mitochondrial fission and reactive oxygen species production which led to activation of ASK1/P38/JNK-mediated apoptosis in colon cancer cells as an important pathway for biselyngbyolide B-mediated cytotoxicity. Notably, this study revealed that a macrolide participated in mitochondrial fission to promote apoptosis of cancer cells, providing new insight.

Anti-angiogenic and anti-tumour activities of Lignosus rhinocerus (Cooke) Ryvarden water extracts on HCT116 human colorectal carcinoma cells implanted in chick embryos

Ethnopharmacological relevanceThe sclerotium of Lignosus rhinocerus (Cooke) Ryvarden is used by the local communities in Southeast Asia and China to treat cancer, asthma, fever, and other ailments based on traditional knowledge. The sclerotial water extracts were previously reported to exhibit cytotoxic, apoptotic, and immunomodulatory activities – providing a scientific basis for its use in treating cancer; however, there is still a lack of evidence on its potential anti-angiogenic activity. Aim of the studyThis study aimed to investigate the toxicity, anti-angiogenic, and anti-tumour activities of the hot-water and cold-water extracts of L. rhinocerus using HCT116 human colorectal carcinoma cells implanted in the chick chorioallantoic membrane (CAM) model. Materials and methodsThe toxicity of L. rhinocerus extracts towards the chick embryos was determined 24 h post-treatment. The anti-angiogenic activity of the extracts was then investigated at 0.1–10 μg/embryo (6.7–670 μg/mL) at targeted blood vessels. The anti-tumour effect of selected extracts against the HCT116 human colorectal carcinoma cells xenografted onto the chick embryos was also studied. ResultsThe cold-water extracts of L. rhinocerus displayed strong in ovo toxicity (LC50: 1.2–37.7 μg/mL) while the hot-water extracts are non-toxic up to 670 μg/mL. Among the extracts, the hot-water extracts demonstrated the highest anti-angiogenic activity with 44.0 ± 17.7% reduction of capillary diameter (relative to the saline-treated control). Moreover, treatment of the HCT116 cells xenografted onto the chick embryos with the hot-water extracts resulted in smaller tumour size and lower number of blood vessels compared to the saline-treated control. ConclusionsThe hot-water extracts of L. rhinocerus sclerotium demonstrated anti-angiogenic and anti-tumour activities but most of the cold-water extracts at similar concentrations were devoid of that. Our findings provide further scientific validation of the medicinal use of the sclerotium in treating cancer and thus, expanding our knowledge on the possible mechanism of its anti-cancer effect apart from direct cytotoxicity, induction of apoptosis and immunomodulation that have been studied thus far.

Proteasome activation is critical for cell death induced by inhibitors of polo-like kinase 1 (PLK1) in multiple cancers

Inhibitors of polo-like kinase (PLK) are currently being evaluated as anticancer drugs. However, the molecular mechanism of PLK inhibitor-induced cell death is not fully understood. In this study, we found that GW843682X and BI2536, two inhibitors of PLK1, significantly induced cell death in multiple type cells. The induction of cell death was related to the preferring expression of PLK1. However, in human umbilical vascular endothelial cells (HUVEC) and human colorectal carcinoma cells, which expressed higher levels of both PLK1 and PLK2, PLK1 inhibitors induced very low levels of cell death. Clinical analysis reveals PLK1 presence in 26 of 30 NPC tumor tissues. In in vivo NPC lung metastasis nude mouse models, PLK1 inhibitors decreased NPC progress. Mechanistically, the PLK1 inhibitor did not activate p53, and the cell death was not reversed by p53 inhibition. Moreover, PLK1 inhibitor-induced cell death was PARP- and caspase-independent. Although PLK1 inhibitors induced down-regulation of calpain inhibitor calpastatin and calpain was activated by PLK1 inhibition, calpain blocking did not reverse cell death induced by PLK1 inhibitors, suggesting the non-involvement of calpain. Surprisingly, we found that PLK1 inhibitors induced the activation of proteasome, and the treatment of cells with PLK1 inhibitors reduced the levels of ubiquitinated proteins. And proteasome inhibitors reversed cell death induced by PLK1 inhibitors in various cell types in which PLK1 was preferentially expressed. Moreover, PLK1 inhibition reversed the degradation of proteins including p53, caspase 8, PARP and calpastatin. These results suggest that the activation of proteasome is critical for cell death induced by PLK1 inhibition.

Anti-inflammatory and Apoptotic Effects of Levisticum Officinale Koch Extracts on HT 29 and Caco-2 Human Colorectal Carcinoma Cell Lines.

Colorectal cancer is among the deadliest cancers in the world. Due to the occurrence of side effects related to current standard therapy, researchers are seeking better alternative treatments. For many years, herbs have been a promising source for discovering therapeutic compounds. Therefore, the primary objective of this research was to examine the distinctive apoptotic and anti-inflammatory properties exhibited by Levisticum officinale Koch (lovage) on HT-29 and Caco-2 cell lines. The maceration method was used to prepare different extracts (ethanol, dichloromethane, petroleum, and residues) from the plant. These extracts were then tested on two colon cancer cell lines - HT-29 and Caco-2 - using the MTT assay to determine the half-maximal inhibitory concentration (IC50) values. In addition, we evaluated the expression levels of several inflammatory genes (IKKb, IKKa, and REIB) using real-time PCR. We also assessed Cox-2 protein expression using western blot analysis. The western blot was also used to analyze apoptosis-related proteins, including Caspase-3, BAX, and Bcl-2. The dichloromethane extract of Levisticum officin (DELO) exhibited a high cytotoxic effect on Caco-2 and HT-29 cell lines, with IC50 values of 106.0±2 μg/mL in HT-29 cells and 175.3±4 μg/mL in Caco-2 cells after 72 hours. None of the lovage extracts showed a significant cytotoxic effect on non-cancerous cells (3T3 cell line). Furthermore, the group treated with DELO showed a lower expression level of inflammatory genes and COX-2 protein compared to the control group. Notably, treatment with DELO resulted in an increase in Caspase-3 protein and BAX/Bcl-2 ratio in both HT-29 and Caco-2 cells. According to this study, DELO has the potential to act as an anti-inflammatory and anti-cancer agent. Further research on the compounds present in DELO and their effect on various signaling pathways could help in the development of new drugs for diseases where inflammation or cells escape from apoptosis play a crucial role.

Abstract LB168: A selective, potent, and orally bioavailable CDK7 inhibitor demonstrates superior anti-cancer activity in colorectal cancer models

Abstract Dysregulated cell cycle and gene expression are pivotal factors in cancer development and the regulators of these processes are attractive targets for cancer treatment. The success of CDK4/6 inhibitors such as palbociclib, ribociclib, and abemaciclib underscores the promising role of targeting cell cycle regulators in anti-cancer therapy. On the other hand, a robust correlation has been established between the overexpression of oncogenes and super-enhancer (SE). The genes associated with SE show increased vulnerability to transcription factor disruption compared to genes with typical enhancers. It has been demonstrated in previous studies that inhibiting transcription factors can effectively decrease the expression of SE-associated oncogenes, including c-MYC, thereby highlighting potential anticancer effects for oncogene-addicted cancers. Currently, agents targeting transcription factors are undergoing clinical trials, offering promising therapeutic options for patients with various types of cancers. CDK7 plays a crucial role in orchestrating cell cycle progression and transcription by phosphorylating CDKs, the C-terminal domain of RNA polymerase II, and hormone receptors like estrogen and androgen receptors. The inhibition of CDK7 has been shown to effectively inhibit tumor growth through various mechanisms, including inducing cell cycle arrest and inhibiting transcription, thereby leading to the death of cancer cells. Notably, ongoing clinical studies have demonstrated that small-molecule CDK7 inhibitors effectively control cancer progression as a stand-alone and in combination with other anti-cancer agents. C-16661, a selective, potent, orally bioavailable, and reversible ATP-competitive inhibitor of CDK7, displayed a single-digit nanomolar IC50 value in both biochemical and cellular assays. It exhibited excellent selectivity in a kinase panel assay, and remarkable potency in a human cancer cell line panel assay. C-16661 treatment resulted in strong inhibition of both its direct and indirect downstream targets including pS5-POLII, pT161-CDK1, c-MYC, and MCL1 in HCT116, a human colorectal carcinoma cell line. While C-16661 exhibited good PK profiles in animals, it demonstrated excellent tumor growth inhibition without any tolerability issues in a colorectal cancer CDX mouse efficacy model. Citation Format: Heuijoon Park, Kyoungwan Seo, Jihyun Yu, Jieun Kim, Min Sung Joo, Sungeun Kim, Joonhyung Lee, Jeonghyeon Lee, Eun-Jung Kim, Joonwoo Nam, Wooseok Han. A selective, potent, and orally bioavailable CDK7 inhibitor demonstrates superior anti-cancer activity in colorectal cancer models [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 LB168.

Lectin-Based Immunophenotyping and Whole Proteomic Profiling of CT-26 Colon Carcinoma Murine Model.

A murine colorectal carcinoma (CRC) model was established. CT26 colon carcinoma cells were injected into BALB/c mice's spleen to study the primary tumor and the mechanisms of cell spread of colon cancer to the liver. The CRC was verified by the immunohistochemistry of Pan Cytokeratin and Vimentin expression. Immunophenotyping of leukocytes isolated from CRC-bearing BALB/c mice or healthy controls, such as CD19+ B cells, CD11+ myeloid cells, and CD3+ T cells, was carried out using fluorochrome-labeled lectins. The binding of six lectins to white blood cells, such as galectin-1 (Gal1), siglec-1 (Sig1), Sambucus nigra lectin (SNA), Aleuria aurantia lectin (AAL), Phytolacca americana lectin (PWM), and galectin-3 (Gal3), was assayed. Flow cytometric analysis of the splenocytes revealed the increased binding of SNA, and AAL to CD3 + T cells and CD11b myeloid cells; and increased siglec-1 and AAL binding to CD19 B cells of the tumor-bearing mice. The whole proteomic analysis of the established CRC-bearing liver and spleen versus healthy tissues identified differentially expressed proteins, characteristic of the primary or secondary CRC tissues. KEGG Gene Ontology bioinformatic analysis delineated the established murine CRC characteristic protein interaction networks, biological pathways, and cellular processes involved in CRC. Galectin-1 and S100A4 were identified as upregulated proteins in the primary and secondary CT26 tumor tissues, and these were previously reported to contribute to the poor prognosis of CRC patients. Modelling the development of liver colonization of CRC by the injection of CT26 cells into the spleen may facilitate the understanding of carcinogenesis in human CRC and contribute to the development of novel therapeutic strategies.

Evaluation of Antiproliferative and Cytotoxic potential of organic solvent fractions of potential plant sources against Human colorectal carcinoma cell lines

People have been relying and using various medicinal sources for ages throughout the world for alleviation of different ailments. Eighty percent of people worldwide depend on herbal medication for their fundamental medical needs, according to a World Health Organization (WHO) survey. The need for plant-based medications has led to increased studies into the extraction of therapeutic properties from plants. Bioactive compounds are secondary metabolites, sometimes termed nutraceuticals, present in food, providing health benefits.

Abstract 4893: Role of MGMT expression in the genomic landscape and immunogenicity in human colorectal carcinomas

Abstract Introduction: Colorectal cancer (CRC) is second most common cause of cancer-related mortality in the USA and most patients with advanced tumors lack effective therapeutic options. Epigenetic silencing resulting in reduced expression of O6-methylguanine-DNA methyltransferase (MGMT) has been described in diverse tumor types including CRC and it is linked with reduced DNA repair capability and increased sensitivity to alkylating agents such as temozolomide. However, the potential role and clinical significance of MGMT overexpression in cancer cells has not been studied. Methods: We used spatially resolved multiplex quantitative immunofluorescence (mQIF) analysis to concurrently measure the levels of MGMT protein, γH2AX and CD8+ tumor infiltrating lymphocytes (TILs) in a cohort of 111 CRCs and paired non-tumor colorectal mucosa from the same patient represented in tissue microarray format. To assess the genomic and immunologic context of MGMT expression, we studied the methylome, mutation profiling and mRNA expression of 526 CRCs from TCGA. The immunologic landscape of tumors was studied using GSEA and multiple transcriptomic-based tumor immune infiltration scores such as TIMER, CIBERSORT, etc. Finally, the genomic alterations and immunogenicity of SW620 human CRC cells (with baseline MGMT hypermethylation) with or without MGMT transfection were studied using in vitro co-culture preparations coupled to ultra-deep DNAseq and flow cytometry analysis. Results: On mQIF analysis, cancer-cell MGMT protein upregulation was identified in 73.9% of CRCs and was associated with reduced levels of γH2Ax in malignant cells and lower CD8+ TILs. 26.1% of cases showed MGMT protein downregulation. The genomic analysis of the TCGA cohort revealed that the mean nonsynonymous mutational load was significantly lower in MGMT-high than low tumors with marked differences in the type of variants and frequency of oncogenic mutations. The transcriptomic analysis revealed that MGMT overexpressing tumors showed lower immune infiltration than the MGMT-low group and reduced representation of immune associated signatures including interferon gamma response and TNF-alpha signaling. In contrast, DNA repair, TP53 pathways, were enriched. The exogenous expression of MGMT in SW620 cells reduced the number of nonsynonymous mutations by 15.6% (141 vs 119 mean mutations) and was also associated with low T-cell activation (CD69+/CD8+ T-cells) and cancer-cell elimination on allogenic co-cultures with human PBMCs. Conclusion: MGMT protein upregulation is common in human CRCs and is associated with reduced DNA damage response, distinct genomic features, and adaptive immune evasion. To our knowledge, this study is the first to report the biological and clinical characteristics of CRCs with MGMT overexpression that could support diagnostic and therapeutic developments. Citation Format: Barani Kumar Rajendran, Janie Zhang, Shruti Desai, Joanna Gibson, Jassim DiPalermo, Patricia LoRusso, Yong Kong, Hongyu Zhao, Michael Cecchini, Kurt Alex Schalper. Role of MGMT expression in the genomic landscape and immunogenicity in human colorectal carcinomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4893.

Abstract 6037: Copper-67 as a next-generation radioconjugate warhead for cancer therapy

Abstract Background and Purpose: Antibody drug conjugates (ADCs) have shown promise as cancer treatments. However, the efficacy of ADCs has been limited in solid tumors and can come with significant toxicities. Radioconjugates utilize various radionuclides that are chelated and can be conjugated to small molecules, peptides and antibodies. We propose Targeted Copper Theranostics (TCTs) which use copper-64 to image tumors and beta-emitting copper-67 to irradiate and kill cancer cells using various molecular targets of oncological relevance. We have evaluated the efficacy of copper-67 based therapy in three formats; peptides, antibodies, and pre-targeting of antibody conjugates in relevant tumor mouse models. Benefits of copper-67 [half-life, 61.8 h; 100% β- energy in the range of 0.18-0.56 MeV] include high purity, high specific activity, manufacturing in a centralized distribution model at high yields on electron accelerators, and half-life suitable to various targeting formats. Copper-64 and copper-67 provide multiple logistical benefits relative to other radionuclides including Ga-68, F-18 and Lu-177. Methods: We evaluated three tumor-targeting moieties conjugated to a sarcophagine bifunctional chelator (SAR), including: a peptide dimer targeting prostate specific membrane antigen (SAR-bisPSMA); an antibody 5B1, targeting the PDAC-specific biomarker carbohydrate antigen-19-9 (CA19-9); and a Tz-TCO IDEEA huA33 antibody/sarcophagine tetrazine conjugate targeting transmembrane glycoprotein A33. Various doses were administered of [67Cu]Cu-SAR-bisPSMA in LNCAP xenografts; [67Cu]Cu-SAR-5B1 (~10 μg) in FC1245 Ft2Ab PDAC tumor-bearing C57BL/6 mice; and [67Cu]Cu-MeCOSAR-Tz in athymic nude mice bearing A33 antigen-expressing SW1222 human colorectal carcinoma xenografts 72 hours after administration of huA33-TCO. Results: Administration of either 7.5, 15 or 30 MBq of [67Cu]Cu-SAR-bisPSMA increased overall survival relative to the control group. Similarly, after administration of 4, 11, 18 MBq of [67Cu]Cu-5B1, treated groups enhanced overall survival to 32 days compared to control (14 days). Pre-targeting using ~18.5, 37.0 or 55.5 MBq or fractionated dosing of two 27.8 MBq doses of [67Cu]Cu-MeCOSAR-Tz showed efficient tumor growth reduction with enhanced overall survival for treated mice pre-administered huA33-TCO, from 68 days to >200 days (dose dependent) compared to control (21 days). Conclusion: We report the inhibition of tumor growth with minimal radiotoxicity and each format demonstrated significantly improved overall survival compared to controls. Collectively our results demonstrated that TCTs using the sarcophagine chelator with copper-67 are effective radioconjugates across multiple formats with an acceptable safety profile. Copper-67-based TCTs are being translated in multiple theranostic clinical trials in the USA and Australia. Citation Format: Matt Harris, Kurt Gehlsen, Lachlan McInnes, Jason Lewis. Copper-67 as a next-generation radioconjugate warhead for cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6037.

The solute carrier SLC7A1 may act as a protein transporter at the blood-brain barrier

Despite extensive research, targeted delivery of substances to the brain still poses a great challenge due to the selectivity of the blood-brain barrier (BBB). Most molecules require either carrier- or receptor-mediated transport systems to reach the central nervous system (CNS). These transport systems form attractive routes for the delivery of therapeutics into the CNS, yet the number of known brain endothelium-enriched receptors allowing the transport of large molecules into the brain is scarce. Therefore, to identify novel BBB targets, we combined transcriptomic analysis of human and murine brain endothelium and performed a complex screening of BBB-enriched genes according to established selection criteria. As a result, we propose the high-affinity cationic amino acid transporter 1 (SLC7A1) as a novel candidate for transport of large molecules across the BBB. Using RNA sequencing and in situ hybridization assays, we demonstrated elevated SLC7A1 gene expression in both human and mouse brain endothelium. Moreover, we confirmed SLC7A1 protein expression in brain vasculature of both young and aged mice. To assess the potential of SLC7A1 as a transporter for larger proteins, we performed internalization and transcytosis studies using a radiolabelled or fluorophore-labelled anti-SLC7A1 antibody. Our results showed that SLC7A1 internalised a SLC7A1-specific antibody in human colorectal carcinoma (HCT116) cells. Moreover, transcytosis studies in both immortalised human brain endothelial (hCMEC/D3) cells and primary mouse brain endothelial cells clearly demonstrated that SLC7A1 effectively transported the SLC7A1-specific antibody from luminal to abluminal side. Therefore, here in this study, we present for the first time the SLC7A1 as a novel candidate for transport of larger molecules across the BBB.

Structural basis for the preservation of a subset of topologically associating domains in interphase chromosomes upon cohesin depletion

Compartment formation in interphase chromosomes is a result of spatial segregation between euchromatin and heterochromatin on a few megabase pairs (Mbp) scale. On the sub-Mbp scales, topologically associating domains (TADs) appear as interacting domains along the diagonal in the ensemble averaged Hi-C contact map. Hi-C experiments showed that most of the TADs vanish upon deleting cohesin, while the compartment structure is maintained, and perhaps even enhanced. However, closer inspection of the data reveals that a non-negligible fraction of TADs is preserved (P-TADs) after cohesin loss. Imaging experiments show that, at the single-cell level, TAD-like structures are present even without cohesin. To provide a structural basis for these findings, we first used polymer simulations to show that certain TADs with epigenetic switches across their boundaries survive after depletion of loops. More importantly, the three-dimensional structures show that many of the P-TADs have sharp physical boundaries. Informed by the simulations, we analyzed the Hi-C maps (with and without cohesin) in mouse liver and human colorectal carcinoma cell lines, which affirmed that epigenetic switches and physical boundaries (calculated using the predicted 3D structures using the data-driven HIPPS method that uses Hi-C as the input) explain the origin of the P-TADs. Single-cell structures display TAD-like features in the absence of cohesin that are remarkably similar to the findings in imaging experiments. Some P-TADs, with physical boundaries, are relevant to the retention of enhancer–promoter/promoter–promoter interactions. Overall, our study shows that preservation of a subset of TADs upon removing cohesin is a robust phenomenon that is valid across multiple cell lines.

Structural basis for the preservation of a subset of topologically associating domains in interphase chromosomes upon cohesin depletion.

Compartment formation in interphase chromosomes is a result of spatial segregation between euchromatin and heterochromatin on a few megabase pairs (Mbp) scale. On the sub-Mbp scales, topologically associating domains (TADs) appear as interacting domains along the diagonal in the ensemble averaged Hi-C contact map. Hi-C experiments showed that most of the TADs vanish upon deleting cohesin, while the compartment structure is maintained, and perhaps even enhanced. However, closer inspection of the data reveals that a non-negligible fraction of TADs is preserved (P-TADs) after cohesin loss. Imaging experiments show that, at the single-cell level, TAD-like structures are present even without cohesin. To provide a structural basis for these findings, we first used polymer simulations to show that certain TADs with epigenetic switches across their boundaries survive after depletion of loops. More importantly, the three-dimensional structures show that many of the P-TADs have sharp physical boundaries. Informed by the simulations, we analyzed the Hi-C maps (with and without cohesin) in mouse liver and human colorectal carcinoma cell lines, which affirmed that epigenetic switches and physical boundaries (calculated using the predicted 3D structures using the data-driven HIPPS method that uses Hi-C as the input) explain the origin of the P-TADs. Single-cell structures display TAD-like features in the absence of cohesin that are remarkably similar to the findings in imaging experiments. Some P-TADs, with physical boundaries, are relevant to the retention of enhancer-promoter/promoter-promoter interactions. Overall, our study shows that preservation of a subset of TADs upon removing cohesin is a robust phenomenon that is valid across multiple cell lines.

Rosemary essential oil potentiates the antitumour activity of 5-fluorouracil in human colorectal carcinoma cells.

Improving response rates in colorectal cancer (CRC) is an urgent clinical need. This study aimed to explore the synergistic action of Lebanese rosemary essential oil (REO) and 5-fluorouracil (5-FU) in HCT116 CRC cells. We tested the cell viability of monotherapy and combination therapy. The combination index was calculated using CompuSyn software to evaluate drug-drug interactions and the level of synergistic cytotoxicity. We also evaluated cell migration and cytopathology. Furthermore, cell apoptosis-related proteins (i.e. Bax and Bcl-2) were measured by Western blot analysis. The REO/5-FU combination synergistically reduced cell viability, effectively decreased cell migration, and increased the Bax/Bcl-2 ratio in HCT116 cells. This triggered a proapoptotic morphology and initiated an apoptotic cascade in HCT116 cells, as indicated by a higher Bax/Bcl-2 ratio. Our results provide evidence of the REO/5-FU combination as a better approach to improve 5-FU anticancer efficacy and allow the use of lower 5-FU doses due to the adjuvant effect of REO.

Unveiling biological activities of biosynthesized starch/silver-selenium nanocomposite using Cladosporium cladosporioides CBS 174.62

Background and objectivesMicrobial cells capability to tolerate the effect of various antimicrobial classes represent a major worldwide health concern. The flexible and multi-components nanocomposites have enhanced physicochemical characters with several improved properties. Thus, different biological activities of biosynthesized starch/silver-selenium nanocomposite (St/Ag-Se NC) were assessed.MethodologyThe St/Ag-Se NC was biosynthesized using Cladosporium cladosporioides CBS 174.62 (C. cladosporioides) strain. The shape and average particle size were investigated using scanning electron microscope (SEM) and high-resolution transmission electron microscope (HR-TEM), respectively. On the other hand, the St/Ag-Se NC effect on two cancer cell lines and red blood cells (RBCs) was evaluated and its hydrogen peroxide (H2O2) scavenging effect was assessed. Moreover, its effects on various microbial species in both planktonic and biofilm growth forms were examined.ResultsThe St/Ag-Se NC was successfully biosynthesized with oval and spherical shape and a mean particle diameter of 67.87 nm as confirmed by the HR-TEM analysis. St/Ag-Se NC showed promising anticancer activity toward human colorectal carcinoma (HCT-116) and human breast cancer (MCF-7) cell lines where IC50 were 21.37 and 19.98 µg/ml, respectively. Similarly, little effect on RBCs was observed with low nanocomposite concentration. As well, the highest nanocomposite H2O2 scavenging activity (42.84%) was recorded at a concentration of 2 mg/ml. Additionally, Staphylococcus epidermidis (S. epidermidis) ATCC 12,228 and Candida albicans (C. albicans) ATCC 10,231 were the highly affected bacterial and fungal strains with minimum inhibitory concentrations (MICs) of 18.75 and 50 µg/ml, respectively. Moreover, the noticeable effect of St/Ag-Se NC on microbial biofilm was concentration dependent. A high biofilm suppression percentage, 87.5% and 68.05%, were recorded with S. epidermidis and Staphylococcus aureus (S. aureus) when exposed to 1 mg/ml and 0.5 mg/ml, respectively.ConclusionThe biosynthesized St/Ag-Se NC showed excellent antioxidant activity, haemocompatibility, and anti-proliferative effect at low concentrations. Also, it exhibited promising antimicrobial and antibiofilm activities.

Modes of Interactions with DNA/HSA Biomolecules and Comparative Cytotoxic Studies of Newly Synthesized Mononuclear Zinc(II) and Heteronuclear Platinum(II)/Zinc(II) Complexes toward Colorectal Cancer Cells.

A series of mono- and heteronuclear platinum(II) and zinc(II) complexes with 4,4',4″-tri-tert-butyl-2,2':6',2″-terpyridine ligand were synthesized and characterized. The DNA and protein binding properties of [ZnCl2(terpytBu)] (C1), [{cis-PtCl(NH3)2(μ-pyrazine)ZnCl(terpytBu)}](ClO4)2 (C2), [{trans-PtCl(NH3)2(μ-pyrazine)ZnCl(terpytBu)}](ClO4)2 (C3), [{cis-PtCl(NH3)2(μ-4,4'-bipyridyl)ZnCl(terpytBu)}](CIO4)2 (C4) and [{trans-PtCl(NH3)2(μ-4,4'-bipyridyl)ZnCl(terpytBu)}](CIO4)2 (C5) (where terpytBu = 4,4',4″-tri-tert-butyl-2,2':6',2″-terpyridine), were investigated by electronic absorption, fluorescence spectroscopic, and molecular docking methods. Complexes featuring transplatin exhibited lower Kb and Ksv constant values compared to cisplatin analogs. The lowest Ksv value belonged to complex C1, while C4 exhibited the highest. Molecular docking studies reveal that the binding of complex C1 to DNA is due to van der Waals forces, while that of C2-C5 is due to conventional hydrogen bonds and van der Waals forces. The tested complexes exhibited variable cytotoxicity toward mouse colorectal carcinoma (CT26), human colorectal carcinoma (HCT116 and SW480), and non-cancerous mouse mesenchymal stem cells (mMSC). Particularly, the mononuclear C1 complex showed pronounced selectivity toward cancer cells over non-cancerous mMSC. The C1 complex notably induced apoptosis in CT26 cells, effectively arrested the cell cycle in the G0/G1 phase, and selectively down-regulated Cyclin D.

Protective benefits of ethyl alcohol extract of Piper betel L. to prevent colon carcinogenesis

Piper betel L. is a traditional nutritional and medicinal food, known for its rich phytochemical components. In the current study, the role of the ethyl alcohol extract of betel leaf (Piper betel) against human colorectal carcinoma (HT29 cells), was investigated. The extract consists of phenolic compounds and flavonoids that are potent antioxidants and antimicrobial agents. Exposure of human colon carcinoma cells, to the 80% ethyl alcohol extract resulted in apoptotic cell death, fragmentation, downregulation in the expression levels of Bcl-XL, and upregulation of p53. The results indicated the inhibition of cell proliferation in a dose-dependent manner. The results highlight the activation of the mitochondrial apoptotic pathway in response to the treatment with ethanolic extracts of betel leaves. The treatment induced DNA damage leading to G1 cell cycle arrest and apoptosis. Low cytotoxicity and anticarcinogenic effects of the ethyl alcohol extracts of betel leaf on HT29 suggest an alternative approach to human colon cancer therapy (combination therapy) and highlights its significance as a functional food or food supplement.

Retraction Note: Syndecan-1 suppresses cell growth and migration via blocking JAK1/STAT3 and Ras/Raf/MEK/ERK pathways in human colorectal carcinoma cells

Retraction Note: Syndecan-1 suppresses cell growth and migration via blocking JAK1/STAT3 and Ras/Raf/MEK/ERK pathways in human colorectal carcinoma cells