Cancer stem cells in progression of colorectal cancer

The epigenetic landscape in intestinal stem cells and its deregulation in colorectal cancer

Epigenetic mechanisms play a pivotal role in controlling gene expression and cellular plasticity in both normal physiology and pathophysiological conditions. These mechanisms are particularly important in the regulation of stem cell self-renewal and differentiation, both in embryonic development and within adult tissues. A prime example of this finely tuned epigenetic control is observed in the gastrointestinal lining, where the small intestine undergoes renewal approximately every 3-5 days. How various epigenetic mechanisms modulate chromatin functions in intestinal stem cells (ISCs) is currently an active area of research. In this review, we discuss the main epigenetic mechanisms that control ISC differentiation under normal homeostasis. Furthermore, we explore the dysregulation of these mechanisms in the context of colorectal cancer (CRC) development. By outlining the main epigenetic mechanisms contributing to CRC, we highlight the recent therapeutics development and future directions for colorectal cancer research.

Integration of single-cell sequencing and bulk RNA-seq to identify and develop a prognostic signature related to colorectal cancer stem cells

The prognosis for patients with colorectal cancer (CRC) remains worse than expected due to metastasis, recurrence, and resistance to chemotherapy. Colorectal cancer stem cells (CRCSCs) play a vital role in tumor metastasis, recurrence, and chemotherapy resistance. However, there are currently no prognostic markers based on CRCSCs-related genes available for clinical use. In this study, single-cell transcriptome sequencing was employed to distinguish cancer stem cells (CSCs) in the CRC microenvironment and analyze their properties at the single-cell level. Subsequently, data from TCGA and GEO databases were utilized to develop a prognostic risk model for CRCSCs-related genes and validate its diagnostic performance. Additionally, functional enrichment, immune response, and chemotherapeutic drug sensitivity of the relevant genes in the risk model were investigated. Lastly, the key gene RPS17 in the risk model was identified as a potential prognostic marker and therapeutic target for further comprehensive studies. Our findings provide new insights into the prognostic treatment of CRC and offer novel perspectives for a systematic and comprehensive understanding of CRC development.

Functional roles of microRNAs in vasculogenic mimicry and resistance to therapy in human cancers: an update

INTRODUCTION

Vasculogenic mimicry (VM) alludes to the ability of cancer cells to organize on three-dimensional channel-like structures to obtain nutrients and oxygen. This mechanism confers an aggressive phenotype, metastatic potential, and resistance to chemotherapy resulting in a poor prognosis. Recent studies have been focused on the identification of microRNAs (miRNAs) that regulate the VM representing potential therapeutic targets in cancer.

AREAS COVERED

An overview of the roles of miRNAs on VM development and their functional relationships with tumor microenvironment. The functions of cancer stem-like cells in VM, and resistance to therapy are also discussed. Moreover, the modulation of VM by natural compounds is explored. The clinical significance of deregulated miRNAs as potential therapeutic targets in tumors showing VM is further highlighted.

EXPERT OPINION

The miRNAs are regulators of protein-encoding genes involved in VM; however, their specific expression signatures with clinical value in large cohorts of patients have not been established yet. We considered that genomic profiling of miRNAs could be useful to define some hallmarks of tumors such as stemness, drug resistance, and VM in cancer patients. However, additional studies are needed to establish the relevant role of miRNAs as effective therapeutic targets in tumors that have developed VM.

Signaling, cancer cell plasticity, and intratumor heterogeneity

Cancer's complexity is in part due to the presence of intratumor heterogeneity and the dynamic nature of cancer cell plasticity, which create substantial obstacles in effective cancer management. Variability within a tumor arises from the existence of diverse populations of cancer cells, impacting the progression, spread, and resistance to treatments. At the core of this variability is the concept of cellular plasticity - the intrinsic ability of cancer cells to alter their molecular and cellular identity in reaction to environmental and genetic changes. This adaptability is a cornerstone of cancer's persistence and progression, making it a formidable target for treatments. Emerging studies have emphasized the critical role of such plasticity in fostering tumor diversity, which in turn influences the course of the disease and the effectiveness of therapeutic strategies. The transformative nature of cancer involves a network of signal transduction pathways, notably those that drive the epithelial-to-mesenchymal transition and metabolic remodeling, shaping the evolutionary path of cancer cells. Despite advancements, our understanding of the precise molecular machinations and signaling networks driving these changes is still evolving, underscoring the necessity for further research. This editorial presents a series entitled "Signaling Cancer Cell Plasticity and Intratumor Heterogeneity" in Cell Communication and Signaling, dedicated to unraveling these complex processes and proposing new avenues for therapeutic intervention.

The Impact of Cancer Stem Cells in Colorectal Cancer

Despite incessant research, colorectal cancer (CRC) is still one of the most common causes of fatality in both men and women worldwide. Over time, advancements in medical treatments have notably enhanced the survival rates of patients with colorectal cancer. Managing metastatic CRC involves a complex tradeoff between the potential benefits and adverse effects of treatment, considering factors like disease progression, treatment toxicity, drug resistance, and the overall impact on the patient's quality of life. An increasing body of evidence highlights the significance of the cancer stem cell (CSC) concept, proposing that CSCs occupy a central role in triggering cancer. CSCs have been a focal point of extensive research in a variety of cancer types, including CRC. Colorectal cancer stem cells (CCSCs) play a crucial role in tumor initiation, metastasis, and therapy resistance, making them potential treatment targets. Various methods exist for isolating CCSCs, and understanding the mechanisms of drug resistance associated with them is crucial. This paper offers an overview of the current body of research pertaining to the comprehension of CSCs in colorectal cancer.

Complexation of histone deacetylase inhibitor belinostat to Cu(II) prevents premature metabolic inactivation in vitro and demonstrates potent anti-cancer activity in vitro and ex vivo in colon cancer

PURPOSE

The histone deacetylase inhibitor (HDACi), belinostat, has had limited therapeutic impact in solid tumors, such as colon cancer, due to its poor metabolic stability. Here we evaluated a novel belinostat prodrug, copper-bis-belinostat (Cubisbel), in vitro and ex vivo, designed to overcome the pharmacokinetic challenges of belinostat.

METHODS

The in vitro metabolism of each HDACi was evaluated in human liver microsomes (HLMs) using mass spectrometry. Next, the effect of belinostat and Cubisbel on cell growth, HDAC activity, apoptosis and cell cycle was assessed in three colon cancer cell lines. Gene expression alterations induced by both HDACis were determined using RNA-Seq, followed by in silico analysis to identify master regulators (MRs) of differentially expressed genes (DEGs). The effect of both HDACis on the viability of colon cancer patient-derived tumor organoids (PDTOs) was also examined.

RESULTS

Belinostat and Cubisbel significantly reduced colon cancer cell growth mediated through HDAC inhibition and apoptosis induction. Interestingly, the in vitro half-life of Cubisbel was significantly longer than belinostat. Belinostat and its Cu derivative commonly dysregulated numerous signalling and metabolic pathways while genes downregulated by Cubisbel were potentially controlled by VEGFA, ERBB2 and DUSP2 MRs. Treatment of colon cancer PDTOs with the HDACis resulted in a significant reduction in cell viability and downregulation of stem cell and proliferation markers.

CONCLUSIONS

Complexation of belinostat to Cu(II) does not alter the HDAC activity of belinostat, but instead significantly enhances its metabolic stability in vitro and targets anti-cancer pathways by perturbing key MRs in colon cancer. Complexation of HDACis to a metal ion might improve the efficacy of clinically used HDACis in patients with colon cancer.

Resveratrol as sensitizer in colorectal cancer plasticity

Despite tremendous medical treatment successes, colorectal cancer (CRC) remains a leading cause of cancer deaths worldwide. Chemotherapy as monotherapy can lead to significant side effects and chemoresistance that can be linked to several resistance-activating biological processes, including an increase in inflammation, cellular plasticity, multidrug resistance (MDR), inhibition of the sentinel gene p53, and apoptosis. As a consequence, tumor cells can escape the effectiveness of chemotherapeutic agents. This underscores the need for cross-target therapeutic approaches that are not only pharmacologically safe but also modulate multiple potent signaling pathways and sensitize cancer cells to overcome resistance to standard drugs. In recent years, scientists have been searching for natural compounds that can be used as chemosensitizers in addition to conventional medications for the synergistic treatment of CRC. Resveratrol, a natural polyphenolic phytoalexin found in various fruits and vegetables such as peanuts, berries, and red grapes, is one of the most effective natural chemopreventive agents. Abundant in vitro and in vivo studies have shown that resveratrol, in interaction with standard drugs, is an effective chemosensitizer for CRC cells to chemotherapeutic agents and thus prevents drug resistance by modulating multiple pathways, including transcription factors, epithelial-to-mesenchymal transition-plasticity, proliferation, metastasis, angiogenesis, cell cycle, and apoptosis. The ability of resveratrol to modify multiple subcellular pathways that may suppress cancer cell plasticity and reversal of chemoresistance are critical parameters for understanding its anti-cancer effects. In this review, we focus on the chemosensitizing properties of resveratrol in CRC and, thus, its potential importance as an additive to ongoing treatments.

POFUT1 and PLAGL2 are characteristic markers of mucinous colorectal cancer associated with MUC2 expression

Colorectal mucinous adenocarcinoma (MAC) is one of the most lethal histological types of colorectal cancer, and its mechanism of development is not well understood. In this study, we aimed to clarify the molecular characteristics of MAC via in silico analysis using The Cancer Genome Atlas database. The expression of genes on chromosome 20q (Chr20q) was negatively associated with the expression of MUC2, which is a key molecule that can be used to distinguish between MAC and nonmucinous adenocarcinoma (NMAC). This was consistent with a significant difference in copy number alteration of Chr20q between the two histological types. We further identified 475 differentially expressed genes (DEGs) between MAC and NMAC, and some of the Chr20q genes among the DEGs are considered to be pivotal genes used to define MAC. Both in vitro and in vivo analysis showed that simultaneous knockdown of POFUT1 and PLAGL2, both of which are located on Chr20q, promoted MUC2 expression. Moreover, these genes were highly expressed in NMAC but not in MAC according to the results of immunohistological studies using human samples. In conclusion, POFUT1 and PLAGL2 are considered to be important for defining MAC, and these genes are associated with MUC2 expression.

Keystone pathobionts associated with colorectal cancer promote oncogenic reprograming

Fusobacterium nucleatum (Fn) and enterotoxigenic Bacteroides fragilis (ETBF) are two pathobionts consistently enriched in the gut microbiomes of patients with colorectal cancer (CRC) compared to healthy counterparts and frequently observed for their direct association within tumors. Although several molecular mechanisms have been identified that directly link these organisms to features of CRC in specific cell types, their specific effects on the epithelium and local immune compartment are not well-understood. To fill this gap, we leveraged single-cell RNA sequencing (scRNA-seq) on wildtype mice and mouse model of CRC. We find that Fn and ETBF exacerbate cancer-like transcriptional phenotypes in transit-amplifying and mature enterocytes in a mouse model of CRC. We also observed increased T cells in the pathobiont-exposed mice, but these pathobiont-specific differences observed in wildtype mice were abrogated in the mouse model of CRC. Although there are similarities in the responses provoked by each organism, we find pathobiont-specific effects in Myc-signaling and fatty acid metabolism. These findings support a role for Fn and ETBF in potentiating tumorigenesis via the induction of a cancer stem cell-like transit-amplifying and enterocyte population and the disruption of CTL cytotoxic function.

PROX1 interaction with α-SMA-rich cancer-associated fibroblasts facilitates colorectal cancer progression and correlates with poor clinical outcomes and therapeutic resistance

BACKGROUND

The tumor microenvironment (TME) plays a vital role in tumor progression through intricate molecular interactions. Cancer-associated fibroblasts (CAFs), notably those expressing alpha-smooth muscle actin (α-SMA) or myofibroblasts, are instrumental in this context and correlate with unfavorable outcomes in colorectal cancer (CRC). While several transcription factors influence TME, the exact regulator causing CAF dysregulation in CRC remains elusive. Prospero Homeobox 1 (PROX1) stands out, as its inhibition reduces α-SMA-rich CAF activity. However, the therapeutic role of PROX1 is debated due to inconsistent study findings.

METHODS

Using the ULCAN portal, we noted an elevated PROX1 level in advanced colon adenocarcinoma, linking to a poor prognosis. Assays determined the impact of PROX1 overexpression on CRC cell properties, while co-culture experiments spotlighted the PROX1-CAF relationship. Molecular expressions were validated by qRT-PCR and Western blots, with in vivo studies further solidifying the observations.

RESULTS

Our study emphasized the connection between PROX1 and α-SMA in CAFs. Elevated PROX1 in CRC samples correlated with increased α-SMA in tumors. PROX1 modulation influenced the behavior of specific CRC cells, with its overexpression fostering invasiveness. Kaplan-Meier evaluations demonstrated a link between PROX1 or α-SMA and survival outcomes. Consequently, PROX1, alone or with α-SMA, emerges as a CRC prognostic marker. Co-culture and animal experiments further highlighted this relationship.

CONCLUSION

PROX1 appears crucial in modulating CRC behavior and therapeutic resistance within the TME by influencing CAFs, signifying the combined PROX1/α-SMA gene as a potential CRC prognostic marker. The concept of developing inhibitors targeting this gene set emerges as a prospective therapeutic strategy. However, this study is bound by limitations, including potential challenges in clinical translation, a focused exploration on PROX1/α-SMA potentially overlooking other significant molecular contributors, and the preliminary nature of the inhibitor development proposition.

c-Fos regulated by TMPO/ERK axis promotes 5-FU resistance via inducing NANOG transcription in colon cancer

Acquired drug resistance is one of the most common limitations for the clinical response of colon cancer to 5-Fluorouracil (5-FU)-based chemotherapy. The relevant molecular mechanisms might be diversity, but still not be elucidated clearly. In this study, we aimed to investigate the potential mechanisms of c-Fos, a subfamily of activator protein-1, in 5-FU chemoresistance. We determined that phosphorylated c-Fos promoted colon cancer cells resistance to 5-FU by facilitating the cancer stemness. Mechanically, 5-FU treatment induced autolysosome-dependent degradation of TMPO, which subsequently triggered ERK-mediated phosphorylation of c-Fos. Additionally, c-Fos was found to bind to the promoter of NANOG and phosphorylation of c-Fos at Ser 374 was required for its regulation of NANOG expression. NANOG ablation impaired c-Fos/p-c-Fos induced 5-FU resistance and stemness. Taken together, these findings revealed that TMPO-mediated phosphorylation of c-Fos conferred 5-FU resistance by regulating NANOG expression and promoting cell stemness in colon cancer cells. c-Fos could be as a therapeutic target for colon cancer.

A Mutation-driven oncofetal regression fuels phenotypic plasticity in colorectal cancer

Targeting cancer stem cells (CSCs) is crucial for effective cancer treatment 1 . However, the molecular mechanisms underlying resistance to LGR5 + CSCs depletion in colorectal cancer (CRC) 2,3 remain largely elusive. Here, we unveil the existence of a primitive cell state dubbed the oncofetal (OnF) state, which works in tandem with the LGR5 + stem cells (SCs) to fuel tumor evolution in CRC. OnF cells emerge early during intestinal tumorigenesis and exhibit features of lineage plasticity. Normally suppressed by the Retinoid X Receptor (RXR) in mature SCs, the OnF program is triggered by genetic deletion of the gatekeeper APC. We demonstrate that diminished RXR activity unlocks an epigenetic circuity governed by the cooperative action of YAP and AP1, leading to OnF reprogramming. This high-plasticity state is inherently resistant to conventional chemotherapies and its adoption by LGR5 + CSCs enables them to enter a drug-tolerant state. Furthermore, through phenotypic tracing and ablation experiments, we uncover a functional redundancy between the OnF and stem cell (SC) states and show that targeting both cellular states is essential for sustained tumor regression in vivo . Collectively, these findings establish a mechanistic foundation for developing effective combination therapies with enduring impact on CRC treatment.

In vitro co-delivery of 5-fluorouracil and all-trans retinoic acid by PEGylated liposomes for colorectal cancer treatment

BACKGROUND

Single-target inhibitors have not been successful in cancer treatment due to the development of drug resistance. Nevertheless, therapeutic agents capable of simultaneously inhibiting multiple targets have revealed encouraging results in inducing apoptosis and overcoming drug resistance in cancerous cells. Here, we designed a composite liposomal nano-carrier co-loading 5-Fluorouracil (5-FU) with all-trans retinoic acid (ATRA) to assess anticancer efficacy of the combined drugs in colorectal cancer (CRC).

METHODS

A PEGylated liposomal nano-carrier with phospholipid/cholesterol/DSPE-PEG (2000) was synthesized by the thin film hydration technique for co-delivery of ATRA and 5-FU. After characterizing, the role of 5-FU and ATRA co-loaded liposomal nano-carrier in proliferation, epithelial-mesenchymal transition (EMT), apoptosis, and cancer stem cells (CSCs) were investigated by using colony forming and MTT assay, RT-qPCR and Annexin V/PI kit.

RESULTS

The average size of liposomes (LPs) was < 150 nm with uniform size distribution. Drug release analyses indicated that both ATRA and 5-FU could simultaneously release from LPs in a sustained release manner. The synergistic inhibitory effects of ATRA and 5-FU loaded in LPs were verified with a combination index of 0.43. Dual drug LPs showed the highest cytotoxicity, enhanced inhibition of cell proliferation, increased apoptotic potential, decreased CSCs, and attenuated EMT-associated biomarkers. Also, dual drug LPs decreased β-catenin gene expression more than other liposomal formulations.

CONCLUSION

These findings suggest that using LPs to achieve a synergistic effect of ATRA and 5-FU is an effectual approach to increase the therapeutic effect of 5-FU toward CRC cells.

Circular RNA ZNF800 (hsa_circ_0082096) regulates cancer stem cell properties and tumor growth in colorectal cancer

BACKGROUND

Cancer stem cells form a rare cell population in tumors that contributes to metastasis, recurrence and chemoresistance in cancer patients. Circular RNAs (circRNAs) are post-transcriptional regulators of gene expression that sponge targeted microRNA (miRNAs) to affect a multitude of downstream cellular processes. We previously showed in an expression profiling study that circZNF800 (hsa_circ_0082096) was up-regulated in cancer stem cell-enriched spheroids derived from colorectal cancer (CRC) cell lines.

METHODS

Spheroids were generated in suspension spheroidal culture. The ZNF800 mRNA, pluripotency stem cell markers and circZNF800 levels were determined by quantitative RT-PCR. CircZNF800-miRNA interactions were shown in RNA pulldown assays and the miRNA levels determined by stem-loop qRT-PCR. The effects of circZNF800 on cell proliferation were tested by EdU staining followed by flowcytometry. Expression of stem cell markers CD44/CD133, Lgr5 and SOX9 was demonstrated in immunofluorescence microscopy. To manipulate the cellular levels of circZNF800, circZNF800 over-expression was achieved via transfection of in vitro synthesized and circularized circZNF800, and knockdown attained using a CRISPR-Cas13d-circZNF800 vector system. Xenografted nude mice were used to demonstrate effects of circZNF800 over-expression and knockdown on tumor growth in vivo.

RESULTS

CircZNF800 was shown to be over-expressed in late-stage tumor tissues of CRC patients. Data showed that circZNF800 impeded expression of miR-140-3p, miR-382-5p and miR-579-3p while promoted the mRNA levels of ALK/ACVR1C, FZD3 and WNT5A targeted by the miRNAs, as supported by alignments of seed sequences between the circZNF800-miRNA, and miRNA-mRNA paired interactions. Analysis in CRC cells and biopsied tissues showed that circZNF800 positively regulated the expression of intestinal stem cell, pluripotency and cancer stem cell markers, and promoted CRC cell proliferation, spheroid and colony formation in vitro, all of which are cancer stem cell properties. In xenografted mice, circZNF800 over-expression promoted tumor growth, while circZNF800 knockdown via administration of CRISPR Cas13d-circZNF800 viral particles at the CRC tumor sites impeded tumor growth.

CONCLUSIONS

CircZNF800 is an oncogenic factor that regulate cancer stem cell properties to lead colorectal tumorigenesis, and may be used as a predictive marker for tumor progression and the CRISPR Cas13d-circZNF800 knockdown strategy for therapeutic intervention of colorectal cancer.

Notch receptor/ligand diversity: contribution to colorectal cancer stem cell heterogeneity

Cancer cell heterogeneity is a key contributor to therapeutic failure and post-treatment recurrence. Targeting cell subpopulations responsible for chemoresistance and recurrence seems to be an attractive approach to improve treatment outcome in cancer patients. However, this remains challenging due to the complexity and incomplete characterization of tumor cell subpopulations. The heterogeneity of cells exhibiting stemness-related features, such as self-renewal and chemoresistance, fuels this complexity. Notch signaling is a known regulator of cancer stem cell (CSC) features in colorectal cancer (CRC), though the effects of its heterogenous signaling on CRC cell stemness are only just emerging. In this review, we discuss how Notch ligand-receptor specificity contributes to regulating stemness, self-renewal, chemoresistance and cancer stem cells heterogeneity in CRC.

FOXM1/NCAPH activates glycolysis to promote colon adenocarcinoma stemness and 5-FU resistance

Chemotherapy using 5-fluorouracil (5-FU) is currently considered the most effective treatment for advanced colon adenocarcinoma (COAD). However, drug resistance remains a major obstacle in treating COAD. Non-SMC condensin I complex subunit H ( NCAPH ) is known to have a certain impact on the development of COAD, but its precise involvement in the mechanism of 5-FU resistance has not been demonstrated. Bioinformatics analysis was utilized to assay the expression of NCAPH and Forkhead box M1 ( FOXM1 ) in COAD tumor tissues, which was then verified in COAD cell lines. The resistance of COAD cells to 5-FU was measured by CCK-8 assay, stemness was tested by cell sphere formation assay, and glycolysis ability was measured by cellular energy analysis metabolism. Chromatin Immunoprecipitation and dual-luciferase reporter assays were done to confirm the specific interaction between FOXM1 and NCAPH . The expression levels of FOXM1 and NCAPH were significantly upregulated in COAD tissues and cells, and they were involved in regulating the glycolytic signaling pathway. Inhibition of the glycolytic pathway could reverse the effect of NCAPH overexpression on COAD stemness and resistance. FOXM1 was identified as a transcription factor of NCAPH , and it regulated COAD glycolysis, cell stemness, and 5-FU resistance by activating NCAPH expression. FOXM1-mediated upregulation of NCAPH expression promoted COAD cell stemness and resistance via the glycolytic pathway. This study provides a possible mechanism for the FOXM1/NCAPH axis in the glycolytic pathway, cell stemness, and resistance in COAD.

Pyrroline-5-Carboxylate Reductase-2 Promotes Colorectal Carcinogenesis by Modulating Microtubule-Associated Serine/Threonine Kinase-like/Wnt/β-Catenin Signaling

BACKGROUND

Despite significant progress in clinical management, colorectal cancer (CRC) remains the third most common cause of cancer-related deaths. A positive association between PYCR2 (pyrroline-5-carboxylate reductase-2), a terminal enzyme of proline metabolism, and CRC aggressiveness was recently reported. However, how PYCR2 promotes colon carcinogenesis remains ill understood.

METHODS

A comprehensive analysis was performed using publicly available cancer databases and CRC patient cohorts. Proteomics and biochemical evaluations were performed along with genetic manipulations and in vivo tumor growth assays to gain a mechanistic understanding.

RESULTS

PYCR2 expression was significantly upregulated in CRC and associated with poor patient survival, specifically among PYCR isoforms (PYCR1, 2, and 3). The genetic inhibition of PYCR2 inhibited the tumorigenic abilities of CRC cells and in vivo tumor growth. Coinciding with these observations was a significant decrease in cellular proline content. PYCR2 overexpression promoted the tumorigenic abilities of CRC cells. Proteomics (LC-MS/MS) analysis further demonstrated that PYCR2 loss of expression in CRC cells inhibits survival and cell cycle pathways. A subsequent biochemical analysis supported the causal role of PYCR2 in regulating CRC cell survival and the cell cycle, potentially by regulating the expression of MASTL, a cell-cycle-regulating protein upregulated in CRC. Further studies revealed that PYCR2 regulates Wnt/β-catenin-signaling in manners dependent on the expression of MASTL and the cancer stem cell niche.

CONCLUSIONS

PYCR2 promotes MASTL/Wnt/β-catenin signaling that, in turn, promotes cancer stem cell populations and, thus, colon carcinogenesis. Taken together, our data highlight the significance of PYCR2 as a novel therapeutic target for effectively treating aggressive colon cancer.

Assessment of Colorectal Cancer Risk Factors through the Application of Network-Based Approaches in a Racially Diverse Cohort of Colon Organoid Stem Cells

Numerous demographic factors have been associated with colorectal cancer (CRC) risk. To better define biological mechanisms underlying these associations, we performed RNA sequencing of stem-cell-enriched organoids derived from the healthy colons of seven European Americans and eight African Americans. A weighted gene co-expression network analysis was performed following RNA sequencing. Module-trait relationships were determined through the association testing of each module and five CRC risk factors (age, body mass index, sex, smoking history, and race). Only modules that displayed a significantly positive correlation for gene significance and module membership were considered for further investigation. In total, 16 modules were associated with known CRC risk factors (p < 0.05). To contextualize the role of risk modules in CRC, publicly available RNA-sequencing data from TCGA-COAD were downloaded and re-analyzed. Differentially expressed genes identified between tumors and matched normal-adjacent tissue were overlaid across each module. Loci derived from CRC genome-wide association studies were additionally overlaid across modules to identify robust putative targets of risk. Among them, MYBL2 and RXRA represented strong plausible drivers through which cigarette smoking and BMI potentially modulated CRC risk, respectively. In summary, our findings highlight the potential of the colon organoid system in identifying novel CRC risk mechanisms in an ancestrally diverse and cellularly relevant population.

Unmasking the Deceptive Nature of Cancer Stem Cells: The Role of CD133 in Revealing Their Secrets

Cancer remains a leading cause of death globally, and its complexity poses a significant challenge to effective treatment. Cancer stem cells and their markers have become key players in tumor growth and progression. CD133, a marker in various cancer types, is an active research area as a potential therapeutic target. This article explores the role of CD133 in cancer treatment, beginning with an overview of cancer statistics and an explanation of cancer stem cells and their markers. The rise of CD133 is discussed, including its structure, functions, and occurrence in different cancer types. Furthermore, the article covers CD133 as a therapeutic target, focusing on gene therapy, immunotherapy, and approaches to affect CD133 expression. Nanoparticles such as gold nanoparticles and nanoliposomes are also discussed in the context of CD133-targeted therapy. In conclusion, CD133 is a promising therapeutic target for cancer treatment. As research in this area progresses, it is hoped that CD133-targeted therapies will offer new and effective treatment options for cancer patients in the future.

Tumor budding as a potential prognostic marker in determining the behavior of primary liver cancers

Hepatocellular (HCC) and intrahepatic cholangiocarcinoma (ICC), the most common primary tumors of the liver, are among the most important causes of cancer deaths worldwide. Because patients with primary liver tumors are frequently diagnosed at an advanced stage and have high mortality, many efforts have been made to identify new markers to determine their behavior and treatment, similar to those in other solid organ tumors. Recently, morphological assessment of tumor budding (TB) has been revealed as a promising prognostic finding to predict tumor behavior and survival across several different tumor types. Currently, the TB score in colorectal cancer has been revealed as an important parameter in pathology report protocols to determine the course of the disease. Regarding the liver, despite enormous data showing that many mechanisms involved in TB are associated with tumor behavior in both HCC and ICC, studies focusing on the role of TB in predicting the behavior and prognosis of these tumors have started to be investigated very recently. The purpose of this review is to present data about TB in primary tumors of the liver, pointing out the potential role of this parameter in determining the course of the disease, and emphasize the need to increase the number of further studies focusing on the evaluation of this parameter with an overview of the mechanisms involved in TB.

Induction of apoptosis in colorectal cancer cells by matrix protein of PPR virus as a novel anti-cancer agent

Colorectal cancer (CRC) is a common and highly malignant neoplasm, ranking as the fourth most frequent cause of cancer-related deaths worldwide. Recently, non-human oncolytic viruses such as Peste des petits ruminants virus (PPRV) are considered as a potent candidate in the viral therapy of cancer. In the current study, the apoptotic effects of matrix (M) protein of PPRV was investigated on SW480 CRC cells. The M gene was cloned into the pcDNA™3.1/Hygro(+) expression vector and transfected into the cancer cells. The cytotoxic effects of the M protein on SW480 cells were confirmed using MTT assay. Furthermore, flow cytometry results showed that the M protein induces apoptosis in 91 % of CRC cells. Interestingly, the expression of the M gene in SW480 cells led to the up-regulation of genes including Bax, p53, and Caspase-9, as well as an increase in the Bax/Bcl-2 ratio. By using bioinformatics modeling, we hypothesized that the M protein could interact with Bax factor through its BH3-like motif and could further activate the intrinsic apoptosis pathway. Ultimately, this study provided the first evidence of the pro-apoptotic activity of PPRV M protein indicating its possible development as a promising novel anti-cancer agent.

A LGR5 reporter pig model closely resembles human intestine for improved study of stem cells in disease

Intestinal epithelial stem cells (ISCs) are responsible for intestinal epithelial barrier renewal; thereby, ISCs play a critical role in intestinal pathophysiology research. While transgenic ISC reporter mice are available, advanced translational studies lack a large animal model. This study validates ISC isolation in a new porcine Leucine Rich Repeat Containing G Protein-Coupled Receptor 5 (LGR5) reporter line and demonstrates the use of these pigs as a novel colorectal cancer (CRC) model. We applied histology, immunofluorescence, fluorescence-activated cell sorting, flow cytometry, gene expression quantification, and 3D organoid cultures to whole tissue and single cells from the duodenum, jejunum, ileum, and colon of LGR5-H2B-GFP and wild-type pigs. Ileum and colon LGR5-H2B-GFP, healthy human, and murine biopsies were compared by mRNA fluorescent in situ hybridization (FISH). To model CRC, adenomatous polyposis coli (APC) mutation was induced by CRISPR/Cas9 editing in porcine LGR5-H2B-GFP colonoids. Crypt-base, green fluorescent protein (GFP) expressing cells co-localized with ISC biomarkers. LGR5-H2B-GFPhi cells had significantly higher LGR5 expression (p < .01) and enteroid forming efficiency (p < .0001) compared with LGR5-H2B-GFPmed/lo/neg cells. Using FISH, similar LGR5, OLFM4, HOPX, LYZ, and SOX9 expression was identified between human and LGR5-H2B-GFP pig crypt-base cells. LGR5-H2B-GFP/APCnull colonoids had cystic growth in WNT/R-spondin-depleted media and significantly upregulated WNT/β-catenin target gene expression (p < .05). LGR5+ ISCs are reproducibly isolated in LGR5-H2B-GFP pigs and used to model CRC in an organoid platform. The known anatomical and physiologic similarities between pig and human, and those shown by crypt-base FISH, underscore the significance of this novel LGR5-H2B-GFP pig to translational ISC research.

EMT/MET plasticity in cancer and Go-or-Grow decisions in quiescence: the two sides of the same coin?

Epithelial mesenchymal transition (EMT) and mesenchymal epithelial transition (MET) are genetic determinants of cellular plasticity. These programs operate in physiological (embryonic development, wound healing) and pathological (organ fibrosis, cancer) conditions. In cancer, EMT and MET interfere with various signalling pathways at different levels. This results in gross alterations in the gene expression programs, which affect most, if not all hallmarks of cancer, such as response to proliferative and death-inducing signals, tumorigenicity, and cell stemness. EMT in cancer cells involves large scale reorganisation of the cytoskeleton, loss of epithelial integrity, and gain of mesenchymal traits, such as mesenchymal type of cell migration. In this regard, EMT/MET plasticity is highly relevant to the Go-or-Grow concept, which postulates the dichotomous relationship between cell motility and proliferation. The Go-or-Grow decisions are critically important in the processes in which EMT/MET plasticity takes the central stage, mobilisation of stem cells during wound healing, cancer relapse, and metastasis. Here we outline the maintenance of quiescence in stem cell and metastatic niches, focusing on the implication of EMT/MET regulatory networks in Go-or-Grow switches. In particular, we discuss the analogy between cells residing in hybrid quasi-mesenchymal states and G_Alert, an intermediate phase allowing quiescent stem cells to enter the cell cycle rapidly.

Cancer stem cells: an insight into the development of metastatic tumors and therapy resistance

The term "cancer stem cells" (CSCs) refers to cancer cells that exhibit traits parallel to normal stem cells, namely the potential to give rise to every type of cell identified in a tumor microenvironment. It has been found that CSCs usually develops from other neoplastic cells or non-cancerous somatic cells by acquiring stemness and malignant characteristics through particular genetic modifications. A trivial number of CSCs, identified in solid and liquid cancer, can give rise to an entire tumor population with aggressive anticancer drug resistance, metastasis, and invasiveness. Besides, cancer stem cells manipulate their intrinsic and extrinsic features, regulate the metabolic pattern of the cell, adjust efflux-influx efficiency, modulate different signaling pathways, block apoptotic signals, and cause genetic and epigenetic alterations to retain their pluripotency and ability of self-renewal. Notably, to keep the cancer stem cells' ability to become malignant cells, mesenchymal stem cells, tumor-associated fibroblasts, immune cells, etc., interact with one another. Furthermore, CSCs are characterized by the expression of particular molecular markers that carry significant diagnostic and prognostic significance. Because of this, scientific research on CSCs is becoming increasingly imperative, intending to understand the traits and behavior of cancer stem cells and create more potent anticancer therapeutics to fight cancer at the CSC level. In this review, we aimed to elucidate the critical role of CSCs in the onset and spread of cancer and the characteristics of CSCs that promote severe resistance to targeted therapy.

Stemness targeting of colorectal cell lines mediated by BAMLET and 5-Flourouracil

PURPOSE

Stemness is the potential for self-renewal and repopulation causing the relapse, progression, and drug resistance of colorectal cancer. We investigated the effects of bovine alpha-lactalbumin made lethal to tumor cells and 5-Flourouracil consisting of bovine α-lactalbumin protein and oleic acid, on colorectal cancer cells on stemness.

METHODS

The quantitative real-time polymerase chain reaction assessed the expression levels of stemness-related genes (c-myc, Lgr5, OCT4). Expression of stemness-related surface markers (CD44 and CD24) was also measured by the flow cytometry technique following the treatments.

RESULTS

Our results indicated decreased expression levels of C-Myc, Lgr5, oct4 as the stemness-related genes (P < 0.0001), and reduced population of CD44⁺ as the stemness-related cell surface marker upon treatment with BAMLET and 5-Flourouracil. BAMLET inhibited the stemness more effectively than 5-Flourouracil (P < 0.0001).

CONCLUSION

Based on the result, inhibition of the Stemness related-genes (C-Myc, Lgr5, Oct4) and the surface markers (CD 24+ and CD44⁺) is a promising therapeutic approach using BAMLET.

Keystone pathobionts associated with colorectal cancer promote oncogenic reprograming

Fusobacterium nucleatum (Fn) and enterotoxigenic Bacteroides fragilis (ETBF) are two pathobionts consistently enriched in the gut microbiomes of patients with colorectal cancer (CRC) compared to healthy counterparts and frequently observed for their direct association within tumors. Although several molecular mechanisms have been identified that directly link these organisms to features of CRC in specific cell types, their specific effects on the epithelium and local immune compartment are not well-understood. To fill this gap, we leveraged single-cell RNA sequencing (scRNA-seq) on wildtype mice and mouse model of CRC. We find that Fn and ETBF exacerbate cancer-like transcriptional phenotypes in transit-amplifying and mature enterocytes in a mouse model of CRC. We also observed increased T cells in the pathobiont-exposed mice, but these pathobiont-specific differences observed in wildtype mice were abrogated in the mouse model of CRC. Although there are similarities in the responses provoked by each organism, we find pathobiont-specific effects in Myc-signaling and fatty acid metabolism. These findings support a role for Fn and ETBF in potentiating tumorigenesis via the induction of a cancer stem cell-like transit-amplifying and enterocyte population and the disruption of CTL cytotoxic function.

Treatment with decitabine induces the expression of stemness markers, PD-L1 and NY-ESO-1 in colorectal cancer: potential for combined chemoimmunotherapy

BACKGROUND

The mechanism of tumor immune escape and progression in colorectal cancer (CRC) is widely investigated in-vitro to help understand and identify agents that might play a crucial role in response to treatment and improve the overall survival of CRC patients. Several mechanisms of immune escape and tumor progression, including expression of stemness markers, inactivation of immunoregulatory genes by methylation, and epigenetic silencing, have been reported in CRC, indicating the potential of demethylating agents as anti-cancer drugs. Of these, a chemotherapeutic demethylating agent, Decitabine (DAC), has been reported to induce a dual effect on both DNA demethylation and histone changes leading to an increased expression of target biomarkers, thus making it an attractive anti-tumorigenic drug.

METHODS

We compared the effect of DAC in primary 1076 Col and metastatic 1872 Col cell lines isolated and generated from patients' tumor tissues. Both cell lines were treated with DAC, and the expression of the NY-ESO-1 cancer-testis antigen, the PD-L1 immunoinhibitory marker, and the CD44, Nanog, KLF-4, CD133, MSI-1 stemness markers were analyzed using different molecular and immunological assays.

RESULTS

DAC treatment significantly upregulated stemness markers in both primary 1076 Col and meta-static 1872 Col cell lines, although a lower effect occurred on the latter: CD44 (7.85 fold; ***p = 0.0001 vs. (4.19 fold; *p = 0.0120), Nanog (4.1 fold; ***p < 0.0001 vs.1.69 fold; ***p = 0.0008), KLF-4 (4.33 fold; ***p < 0.0001 vs.2.48 fold; ***p = 0.0005), CD133 (16.77 fold; ***p = 0.0003 vs.6.36 fold; *p = 0.0166), and MSI-1 (2.33 fold; ***p = 0.0003 vs.2.3 fold; ***p = 0.0004), respectively. Interestingly, in the metastatic 1872 Col cells treated with DAC, the expression of both PD-L1 and NY-ESO-1 was increased tenfold (*p = 0.0128) and fivefold (***p < 0.0001), respectively.

CONCLUSIONS

We conclude that the upregulation of both stemness and immune checkpoint markers by DAC treatment on CRC cells might represent a mechanism of immune evasion. In addition, induction of NY-ESO-1 may represent an immuno-therapeutic option in metastatic CRC patients. Finally, the combination of DAC and anti-PD-1/anti-PD-L1 antibodies treatment should represent a potential therapeutic intervention for this group of patients.

Anticancer Potential of Apigenin and Isovitexin with Focus on Oncogenic Metabolism in Cancer Stem Cells

It has been demonstrated that cancer stem cells (CSCs) go through metabolic changes that differentiate them from non-CSCs. The altered metabolism of CSCs plays a vital role in tumor initiation, progression, immunosuppression, and resistance to conventional therapy. Therefore, defining the role of CSC metabolism in carcinogenesis has emerged as a main focus in cancer research. Two natural flavonoids, apigenin and isovitexin, have been shown to act synergistically with conventional chemotherapeutic drugs by sensitizing CSCs, ultimately leading to improved therapeutic efficacy. The aim of this study is to present a critical and broad evaluation of the anti-CSC capability of apigenin and isovitexin in different cancers as novel and untapped natural compounds for developing drugs. A thorough review of the included literature supports a strong association between anti-CSC activity and treatment with apigenin or isovitexin. Additionally, it has been shown that apigenin or isovitexin affected CSC metabolism and reduced CSCs through various mechanisms, including the suppression of the Wnt/β-catenin signaling pathway, the inhibition of nuclear factor-κB protein expression, and the downregulation of the cell cycle via upregulation of p21 and cyclin-dependent kinases. The findings of this study demonstrate that apigenin and isovitexin are potent candidates for treating cancer due to their antagonistic effects on CSC metabolism.

Inflammation-Related Signature Profile Expression as a Poor Prognosis Marker after Oxaliplatin Treatment in Colorectal Cancer

Oxaliplatin is successfully used to eradicate micro-metastasis and improve survival, whereas the benefit of adjuvant chemotherapy in the early stages of colorectal cancer remains controversial. Inflammation plays a crucial role in colorectal cancer tumorigenesis. Inflammatory mechanisms are mediated by different immune cells through different cytokines, chemokines, and other proinflammatory molecules that trigger cell progression, an increase of cancer stem cell population, hyperplasia, and metastasis. This study focuses on the analysis of the oxaliplatin effect on tumourspheres formation efficiency, cell viability, cancer stem cells and stemness marker mRNA expression, as well as inflammation-related signature profile expression and its prognosis in primary- and metastatic-derived colorectal tumourspheres derived from colorectal cell lines isolated from the same patient 1 year apart. The results indicate that primary-derived colorectal tumourspheres respond to oxaliplatin, adapting to the adverse conditions through the modulation of CSCs and the stemness properties of tumourspheres. However, metastatic-derived colorectal tumourspheres response led to the release of cytokines and chemokines, promoting an inflammatory process. In addition, the expression of inflammatory markers showing greater difference between primary and metastatic tumours after oxaliplatin treatment correlates with poor prognosis in KM survival studies and is associated with a metastatic phenotype. Our data demonstrated that oxaliplatin triggers an inflammation-related signature profile expression in primary-derived colorectal tumourspheres, related with poor prognosis and a metastatic phenotype, which allow the tumour cells to adapt to the adverse condition. These data highlight the need for of drug testing and personalized medicine in the early stages of colorectal cancer.

Cancer stem cells in colorectal cancer: Signaling pathways involved in stemness and therapy resistance

Colorectal cancer (CRC) is the third cause of cancer death worldwide. Although, in some cases, treatment can increase patient survival and reduce cancer recurrence, in many cases, tumors can develop resistance to therapy leading to recurrence. One of the main reasons for recurrence and therapy resistance is the presence of cancer stem cells (CSCs). CSCs possess a self-renewal ability, and their stemness properties lead to the avoidance of apoptosis, and allow a new clone of cancer cells to emerge. Numerous investigations inidicated the involvment of cellular signaling pathways in embryonic development, and growth, repair, and maintenance of tissue homeostasis, also participate in the generation and maintenance of stemness in colorectal CSCs. This review discusses the role of Wnt, NF-κB, PI3K/AKT/mTOR, Sonic hedgehog, and Notch signaling pathways in colorectal CSCs, and the possible modulating drugs that could be used in treatment for resistant CRC.

Cancer Stem Cell Relationship with Pro-Tumoral Inflammatory Microenvironment

Inflammatory processes and cancer stem cells (CSCs) are increasingly recognized as factors in the development of tumors. Emerging evidence indicates that CSCs are associated with cancer properties such as metastasis, treatment resistance, and disease recurrence. However, the precise interaction between CSCs and the immune microenvironment remains unexplored. Although evasion of the immune system by CSCs has been extensively studied, new research demonstrates that CSCs can also control and even profit from the immune response. This review provides an overview of the reciprocal interplay between CSCs and tumor-infiltrating immune cells, collecting pertinent data about how CSCs stimulate leukocyte reprogramming, resulting in pro-tumor immune cells that promote metastasis, chemoresistance, tumorigenicity, and even a rise in the number of CSCs. Tumor-associated macrophages, neutrophils, Th17 and regulatory T cells, mesenchymal stem cells, and cancer-associated fibroblasts, as well as the signaling pathways involved in these pro-tumor activities, are among the immune cells studied. Although cytotoxic leukocytes have the potential to eliminate CSCs, immune evasion mechanisms in CSCs and their clinical implications are also known. We intended to compile experimental findings that provide direct evidence of interactions between CSCs and the immune system and CSCs and the inflammatory milieu. In addition, we aimed to summarize key concepts in order to comprehend the cross-talk between CSCs and the tumor microenvironment as a crucial process for the effective design of anti-CSC therapies.

Absence of Scaffold Protein Tks4 Disrupts Several Signaling Pathways in Colon Cancer Cells

Tks4 is a large scaffold protein in the EGFR signal transduction pathway that is involved in several cellular processes, such as cellular motility, reactive oxygen species-dependent processes, and embryonic development. It is also implicated in a rare developmental disorder, Frank-ter Haar syndrome. Loss of Tks4 resulted in the induction of an EMT-like process, with increased motility and overexpression of EMT markers in colorectal carcinoma cells. In this work, we explored the broader effects of deletion of Tks4 on the gene expression pattern of HCT116 colorectal carcinoma cells by transcriptome sequencing of wild-type and Tks4 knockout (KO) cells. We identified several protein coding genes with altered mRNA levels in the Tks4 KO cell line, as well as a set of long non-coding RNAs, and confirmed these changes with quantitative PCR on a selected set of genes. Our results show a significant perturbation of gene expression upon the deletion of Tks4, suggesting the involvement of different signal transduction pathways over the well-known EGFR signaling.

The Role of Cancer Stem Cells and Their Extracellular Vesicles in the Modulation of the Antitumor Immunity

Cancer stem cells (CSCs) are a population of tumor cells that share similar properties to normal stem cells. CSCs are able to promote tumor progression and recurrence due to their resistance to chemotherapy and ability to stimulate angiogenesis and differentiate into non-CSCs. Cancer stem cells can also create a significant immunosuppressive environment around themselves by suppressing the activity of effector immune cells and recruiting cells that support tumor escape from immune response. The immunosuppressive effect of CSCs can be mediated by receptors located on their surface, as well as by secreted molecules, which transfer immunosuppressive signals to the cells of tumor microenvironment. In this article, the ability of CSCs to regulate the antitumor immune response and a contribution of CSC-derived EVs into the avoidance of the immune response are discussed.

Sequential Treatment with Activin and Hepatocyte Growth Factor Induces FOXM1 to Promote Colorectal Cancer Liver Metastasis

BACKGROUND

Cancer stem cells (CSCs) are involved in liver metastasis in colorectal cancer (CRC). Activin and hepatocyte growth factor (HGF) are important regulators of stem cell properties. This study was performed to explore the effect of activin and HGF on CRC invasion and metastasis. The key genes involved in the action of activin and HGF in CRC were identified.

METHODS

HCT116 CRC cells were sequentially treated with activin and HGF and examined for migration and invasion in vitro and liver metastasis in vivo. RNA sequencing was performed to identify differentially expressed genes in response to activin and HGF.

RESULTS

Sequential treatment with activin and HGF-enhanced CRC cell migration, invasion, and metastasis. CXCR4 and AFP expressions were increased by activin and HGF treatment. Knockdown of FOXM1 blocked liver metastasis from HCT116 cells pretreated with activin and HGF and suppressed CXCR4 and AFP expression. Activin alone increased the mRNA and protein expression of FOXM1. In contrast, HGF alone enhanced the phosphorylation of FOXM1, without altering the total protein level of FOXM1. SMAD2 was required for activin-mediated FOXM1 induction. FOXM1 transactivated CXCR4 by directly binding to the promoter of CXCR4. Additionally, CXCR4 regulated AFP expression through the NF-κB pathway.

CONCLUSIONS

Sequential treatment with activin and HGF accelerates CRC invasion and liver metastasis, which involves the upregulation and activation of FOXM1 and induction of CXCR4 and AFP.

Nectins and Nectin-like Molecules in Colorectal Cancer: Role in Diagnostics, Prognostic Values, and Emerging Treatment Options: A Literature Review

In 2020, colorectal cancer was the third most common type of cancer worldwide with a clearly visible increase in the number of cases each year. With relatively high mortality rates and an uncertain prognosis, colorectal cancer is a serious health problem. There is an urgent need to investigate its specific mechanism of carcinogenesis and progression in order to develop new strategies of action against this cancer. Nectins and Nectin-like molecules are cell adhesion molecules that take part in a plethora of essential processes in healthy tissues as well as mediating substantial actions for tumor initiation and evolution. Our understanding of their role and a viable application of this in anti-cancer therapy has rapidly improved in recent years. This review summarizes the current data on the role nectins and Nectin-like molecules play in colorectal cancer.

Tumour budding is a novel marker in breast cancer: the clinical application and future prospects

Breast cancer (BC) is a group of markedly heterogeneous tumours. There are many subtypes with different biological behaviours and clinicopathological characteristics, leading to significantly different prognosis. Despite significant advances in the treatment of BC, early metastatic is a critical factor for poor prognosis in BC patients. Tumour budding (TB) is considered as the first step process of tumour metastasis and is related to the epithelial-mesenchymal transition (EMT). TB has been observed in a variety of cancers, such as colorectal and gastric cancer, and had been considered as a distinct clinicopathological characteristics for early metastasis. However, TB evaluation standards and clinical application are not uniform in BC, as well as its molecular mechanism is not fully understood. Here, we reviewed the interpretation criteria, mechanism, clinicopathological characteristics and clinical application prospects of TB in BC. Key messagesCurrently, tumour budding is a poor prognosis for various solid tumours, also in breast cancer.Tumour budding is based on epithelial-mesenchymal transition and tumour microenvironment factors and is presumed to be an early step in the metastatic process.Breast cancer tumour budding still needs multi-centre experiments. We summarize the current research on breast cancer tumour budding, analyse the method of discriminating breast cancer tumour budding and explore the prognostic role and mechanism in breast cancer.

Chemokines in colon cancer progression

Colon cancer is a major human cancer accounting for about a tenth of all cancer cases thus making it among the top three cancers in terms of incidence as well as mortality. Metastasis to distant organs, particularly to liver, is the primary reason for associated mortality. Chemokines, the chemo-attractants for various immune cells, have increasingly been reported to be involved in cancer initiation and progression, including in colon cancer. Here we discuss the available knowledge on the role of several chemokines, such as, CCL2, CCL3, CCL5, CXCL1, CXCL2, CXCL8 in colon cancer progression. CCL20 is one chemokine with emerging evidence for its role in influencing colon cancer tumor microenvironment through the documents effects on fibroblasts, macrophages and immune cells. We focus on CCL20 and its receptor CCR6 as promising factors that affect multiple levels of colon cancer progression. They interact with several cytokines and TLR receptors leading to increased aggressiveness, as supported by multitude of evidence from in vitro, in vivo studies as well as human patient samples. CCL20-CCR6 bring about their biological effects through regulation of several signaling pathways, including, ERK and NF-κB pathways, in addition to the epithelial-mesenchymal transition. Signaling involving CCL20-CCR6 has profound effect on colon cancer hepatic metastasis. Combined with elevated CCL20 levels in colon tumors and metastatic patients, the above information points to a need for further evaluation of chemokines as diagnostic and/or prognostic biomarkers.

Impact of a haplotype (composed of the APC, KRAS, and TP53 genes) on colorectal adenocarcinoma differentiation and patient prognosis

BACKGROUND

Many types of gene mutation are associated with the drug resistance of cancer cells. XELOX is a new and efficient surgical adjuvant chemotherapy for colorectal adenocarcinoma. However, drug-resistant related genetic mutations associated with this treatment remain unknown.

METHODS

Next-generation sequencing (NGS) was performed on 36 colorectal cancer patients to identify mutations among patients with residual tumors following preoperative chemotherapy. Enrichment and prognosis of these mutations were evaluated in a TCGA cohort. The pathology of cases with poor prognosis-related mutations was also determined.

RESULTS

A sequence of SNPs associated with the APC, KRAS, and TP53 genes in 13 of 19 subjects with residual tumors after preoperative chemotherapy was identified. Using survival analysis data from 317 cases in the TCGA database, a prognosis-related haplotype composed of SNPs from APC, KRAS, and TP53 was assembled. Colorectal cancer patients with these mutations had a lower 5-year tumor-specific survival rate than those without (p < 0.05). Most patients with these mutations were at a higher clinical stage (III-IV) of disease. Enrolled subjects with the identified haplotype tended to have poor cancer cell differentiation.

CONCLUSIONS

The prognosis-related haplotype can be used as a marker of drug resistance and prognosis in colorectal cancer patients after preoperative chemotherapy.

GANT61 exerts anticancer cell and anticancer stem cell capacity in colorectal cancer by blocking the Wnt/β‑catenin and Notch signalling pathways

The present study aimed to assess the anticancer cell and anticancer stem cell (CSC) effects of GANT61, and its regulatory influence on the Wnt/β-catenin and Notch signalling pathways in colorectal cancer (CRC). HT-29 and HCT-116 cells were treated with 0, 2.5, 5, 10, 20 or 40 µM GANT61, after which relative cell viability and the expression of Gli1, β-catenin and Notch1, as well as the percentage of CD133⁺ cells, were detected. Subsequently, HT-29/HCT-116 cells and CSCs were treated with 20 µM GANT61, 10 mM of the Wnt/β-catenin pathway agonist HLY78, and 30 mM of the Notch pathway agonist JAG1 (alone or in combination), which was followed by the assessment of cell viability and apoptosis. In both cell lines, GANT61 reduced relative cell viability in a time- and dose-dependent manner, inhibited Gli1, β-catenin and Notch1 expression, and decreased the percentage of CD133⁺ cells in a dose-dependent manner. Furthermore, HLY78 and JAG1 were both found to improve the relative viability, while downregulating the apoptosis of untreated and GANT61-treated HT-29 and HCT-116 cells. Moreover, Wnt/β-catenin and Notch signalling pathway activity were upregulated in CSCs isolated from HT-29 and HCT-116 cells, compared with the associated control groups. GANT61 also reduced the viability of HT-29 and HCT-116 cells and increased apoptosis, whereas HLY78 and JAG1 treatment resulted in the opposite effect. Moreover, both HLY78 and JAG1 attenuated the effects of GANT61 on cellular viability and apoptosis. In conclusion, GANT61 was found to effectively eliminate cancer cells and CSCs by blocking the Wnt/β-catenin and Notch signalling pathways in CRC.

Preoperative low absolute lymphocyte count to fibrinogen ratio correlated with poor survival in nonmetastatic colorectal cancer

Background

Preoperative absolute lymphocyte count (LC) and fibrinogen (FIB) are useful prognostic indicators in colorectal cancer (CRC). However, the prognostic value of the LC to FIB ratio (LFR) has never been addressed.

Methods

A total of 189 nonmetastatic CRC patients after resection were enrolled retrospectively. The significance of the LFR in predicting disease-free survival (DFS) and overall survival (OS) was estimated by receiver operating characteristic curve analysis, and the prognostic efficacy was compared with individual LC and FIB. Patients were assigned to LFR low or high subgroups. Differences in clinicopathological features among these subgroups were calculated, and the survival differences of these subgroups were determined by the Kaplan-Meier analysis. A Cox proportional hazards model was applied to test the risk factors for survival.

Results

Taking 0.54 as the optimal cutoff point, the LFR had sensitivities of 79.70% and 86.40% and specificities of 52.30% and 51.00% in predicting the DFS and OS, respectively. A total of 109/189 (57.67%) patients were assigned to the LFR low group, and these patients were more likely to be characterized by criteria such as T₃ + T₄ (P < 0.01), stage 3 (P < 0.01), tumor deposits (P = 0.01), high CEA (P < 0.01), or CA19-9 levels (P = 0.04). And they also displayed worse DFS (log rank = 18.57, P < 0.01) and OS (log rank = 20.40, P < 0.01) than the high LFR group. Finally, the LFR was independently associated with inferior DFS (HR = 0.32, 95% CI: 0.16–0.61, P < 0.01) and OS (HR = 0.23, 95% CI: 0.09–0.55, P < 0.01).

Conclusions

The LFR is a useful prognostic indicator in nonmetastatic CRC, and patients with a relatively low LFR had poor survival.

Modulating the Siah2-PHD3-HIF1α axis and/or autophagy potentially retard colon cancer proliferation possibly, due to the damping of colon cancer stem cells

BACKGROUND

Hypoxic microenvironment of colon cancer is associated with HIF-1α upregulation. HIF-1α response elements are responsible for autophagy induction that promotes tumor proliferation. Moreover, HIF-1α induces tumor cell proliferation via maintaining cancer stem cells (CSCs) survival. Siah2 is E3 ubiquitin ligase that indirectly stabilizes HIF-1α. We hypothesized that dual inhibition of Siah2 as well as autophagy could be a promising approach that may inhibit CSCs growth.

AIM OF THE WORK

This study investigated the possible effect of vitamin K3 as a Siah2 inhibitor and hydroxychloroquine as an autophagy inhibitor in colon cancer management. The effect (if any) of these agents on CSCs growth will be also manipulated.

METHODS

Colon cancer was induced by dimethylhydrazine. MDA and GSH were selected as oxidative stress markers, Expression of HIF-1α, Caspase-3, VEGF, MMP-9, EpCAM, SCF, and CA19.9 were assayed using immunoassay. The Western blot technique was used to assess LC3Ⅰ, CD44, and CD133 whereas RT-PCR was used to investigate PHD3 and CD44 in colon tissues. Additionally, Ki-67 and Siah2 were detected immunohistochemically.

RESULTS

vitamin K3 and hydroxychloroquine either alone or in combination downregulated the expression of Siah2 and HIF-1α through upregulating PHD3 in colon tissues. This combination significantly downregulated MDA, Ki-67, VEGF, and MMP-9 expression and upregulated the expression of GSH and caspase-3. LC3Ⅰ was also upregulated. Interestingly, these therapeutic options were correlated with down-regulation of the cancer stem cell marker such as CD44 and EpCAM.

CONCLUSION

Our results suggested that suppression of both Siah2-PHD3-HIF-1α axis and autophagy retard colon cancer proliferation and dampened CSCs.

Expression and Prognostic Significance of Stem Cell Marker CD133 in Survival Rate of Patients with Colon Cancer

INTRODUCTION

Today, colon cancer is one of the most common types of gastrointestinal cancer worldwide. CD133 as a known cancer stem cell marker has been found effective in cell proliferation and differentiation in various cancers, including colon cancer. We aimed to investigate the relationship between CD133 expression in colon cancer with prognostic factors and survival rate of patients with colon cancer by immunohistochemistry.

METHODS

Formalin-fixed paraffin-embedded (FFPE) tissue was taken from patients with colon cancer. Histopathology examination was done using hematoxylin and eosin staining. Immunohistochemistry was performed to determine CD133 expression. Association between CD133 expression and clinicopathological profile was then assessed.

RESULTS

There was a statistically significant association between CD133 protein expression and sex , cancer stage, and lymphatic invasion (p = 0.044, p = 0.131, and p = 0.002, respectively). However, no significant correlation was identified between CD133 expression and other factors, including age of patients with colorectal cancer (CRC) (p = 0.267), tumor location (p = 0.494), tumor differentiation grade (p = 0.263), neural tissue invasion, and 5-year survival (p = 0.054).

CONCLUSION

CD133 is a useful predictive or prognostic biomarker for CRC in clinical assessment and may serve as a potential therapeutic target for CRC.

dN/dS-H, a New Test to Distinguish Different Selection Modes in Protein Evolution and Cancer Evolution

One of the most popular measures in the analysis of protein sequence evolution is the ratio of nonsynonymous distance (d_N) to synonymous distance (d_S). Under the assumption that synonymous substitutions in the coding region are selectively neutral, the d_N/d_S ratio can be used to statistically detect the adaptive evolution (or purifying selection) if d_N/d_S > 1 (or d_N/d_S < 1) significantly. However, due to strong structural constraints and/or variable functional constraints imposed on amino acid sites, most encoding genes in most species have demonstrated d_N/d_S < 1. Consequently, the statistical power for testing d_N/d_S = 1 may be insufficient to distinguish between different selection modes. In this paper, we propose a more powerful test, called d_N/d_S-H, in which a new parameter H, a relative measure of rate variation among sites, was introduced. Given the condition of strong purifying selections at some sites, the d_N/d_S-H model predicts d_N/d_S = 1-H for neutral evolution, d_N/d_S < 1-H for nearly neutral selection, and d_N/d_S > 1-H for adaptive evolution. The potential of this new method for resolving the neutral-adaptive debates is illustrated by the protein sequence evolution in vertebrates, Drosophila and yeasts, as well as somatic cancer evolution (specialized as the C_N/C_S-H test).

Detection of Glycosylated Markers From Cancer Stem Cells With ColoSTEM Dx Kit for Earlier Prediction of Colon Cancer Aggressiveness

Nowadays, colon cancer prognosis still difficult to predict, especially in the early stages. Recurrences remain elevated, even in the early stages after curative surgery. Carcidiag Biotechnologies has developed an immunohistochemistry (IHC) kit called ColoSTEM Dx, based on a MIX of biotinylated plant lectins that specifically detects colon cancer stem cells (CSCs) through glycan patterns that they specifically (over)express. A retrospective clinical study was carried out on tumor tissues from 208 non-chemotherapeutic-treated and 21 chemotherapeutic-treated patients with colon cancer, which were stained by IHC with the MIX. Clinical performances of the kit were determined, and prognostic and predictive values were evaluated. With 78.3% and 70.6% of diagnostic sensitivity and specificity respectively, our kit shows great clinical performances. Moreover, patient prognosis is significantly poorer when the MIX staining is “High” compared to “Low”, especially at 5-years of overall survival and for early stages. The ColoSTEM Dx kit allows an earlier and a more precise determination of patients’ outcome. Thus, it affords an innovating clinical tool for predicting tumor aggressiveness earlier and determining prognosis value regarding therapeutic response in colon cancer patients.

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

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

Inhibition of the AKT signaling cascade by GSK690693 may serve as an alternative to improve the irinotecan response in EVI1-expressing colon cancer cells.

Comprehensive analysis of the PD-L1 and immune infiltrates of N6-methyladenosine related long non-coding RNAs in bladder cancer

Bladder cancer (BLCA) is one of the most frequent genitourinary cancers, with a high rate of morbidity and mortality. The connection of m6A-related lncRNAs with PD-L1 and tumor immune microenvironment (TIME) in BLCA prognosis was extensively investigated in this study, which could suggest novel therapeutic targets for further investigation. 30 m6A-associated lncRNAs with predictive values from the TCGA data set were identified with co-expression analysis. Cluster2 was correlated with a poor prognosis, upregulated PD-L1 expression, and higher immune ratings. Cluster2 had larger amounts of resting CD4 memory-activated T cells, M2 macrophages, neutrophils, and NK cells infiltration. "CHEMOKINE SIGNALING PATHWAY" was the most significantly enriched signaling pathway according to GSEA, which may play an important role in the different immune cell infiltrates between cluster1/2. The risk model for m6A-related lncRNAs could be employed in a prognostic model to predict BLCA prognosis, regardless of other clinical features. Collectively, m6A-related lncRNAs were linked to PD-L1 and TIME, which would dynamically affect the number of tumor-infiltrating immune cells. m6A-related lncRNAs may be key mediators of PD-L1 expression and immune cells infiltration and may strongly affect the TIME of BLCA.

Cancer stem cell marker expression and methylation status in patients with colorectal cancer

The number of individuals diagnosed with colorectal cancer (CRC) has been on an alarming upward trajectory over the past decade. In some countries, this cancer represents one of the most frequently diagnosed types of neoplasia. Therefore, it is an important demand to study the pathology underlying this disease to gain insights into the mechanism of resistance to treatment. Resistance of tumors to chemotherapy and tumor aggressiveness have been associated with a minor population of neoplastic cells, which are considered to be responsible for tumor recurrence. These types of neoplastic cells are known as cancer stem cells, which have been previously reported to serve an important role in pathogenesis of this malignant disease. Slovakia has one of the highest incidence rates of CRC worldwide. In the present study, the aim was to classify the abundance of selected stem cell markers (CD133, CD166 and Lgr5) in CRC tumors using flow cytometry. In addition, the methylation status of selected genomic regions of CRC biomarkers (ADAMTS16, MGMT, PROM1 (CD133), LGR5 and ALCAM) was investigated by pyrosequencing in a cohort of patients from Martin University Hospital, Martin, Slovakia. Samples from both primary tumors and metastatic tumors were tested. Analysis of DNA methylation in the genomic regions of indicated five CRC biomarkers was also performed, which revealed the highest levels of methylation in the A disintegrin and metalloproteinase with thrombospondin motifs 16 and O6-methyguanine-DNA methyl transferase genes, whereas the lowest levels of methylation were found in genes expressing prominin-1, leucine-rich repeat-containing G-protein-coupled receptor 5 and activated leukocyte cell adhesion molecule. Furthermore, tumor tissues from metastases showed significantly higher levels of CD133⁺ cells compared with that in primary tumors. Higher levels of CD133⁺ cells correlated with TNM stage and the invasiveness of CRC into the lymphatic system. Although relatively small number of samples was processed, CD133 marker was consider to be important marker in pathology of CRC.

Methionine restriction enhances the chemotherapeutic sensitivity of colorectal cancer stem cells by miR-320d/c-Myc axis

Chemotherapy resistance of colorectal cancer stem cells (CRC-SCs) has become a major challenge in clinical treatment of cancer. Methionine restriction (MR) enhances the therapeutic effect of chemotherapeutic agents. The aim of this study was to explore the molecular pathways that MR affects the chemotherapeutic sensitivity of CRC-SCs. CD133⁺ and CD133^- SW480 or SW620 cells were isolated by magnetic-activated cell sorting (MACS). Mouse xenograft tumor model was established by subcutaneous inoculation of CD133⁺ SW480. MTT assay was used to detect cell viability. Phase distribution of cell cycle was detected by flow cytometry. Western blotting was used to detect drug-resistant related protein expression. miR-320d and transcription factor c-Myc expressions were detected by qRT-PCR. The interaction between miR-320d and c-Myc was verified by luciferase assay. CD133⁺ SW480 and SW620 cells were more resistant to 5-fluorouracil (5-FU) than CD133^- cells. In vitro and in vivo experiments showed that 5-FU and MR combined therapy further inhibited CD133⁺ cell activity and ATP binding cassette subfamily G member 2 (ABCG2) expression, and reduced tumor volume compared with drug administration alone. Interference with miR-320d or overexpression of c-Myc reversed the increased chemotherapeutic sensitivity of CRC-SCs induced by synergistic therapy with 5-FU and MR. miR-320d can target and regulate c-Myc. Interference with c-Myc could reverse the increase in cell viability and ABCG2 expression caused by down-regulation of miR-320d. In conclusion, the combined chemotherapy with MR can enhance the chemotherapeutic sensitivity of CRC-SCs by up-regulation of miR-320d to inhibit c-Myc expression, which lays a molecular basis for MR regulation of chemotherapeutic sensitivity of CRC-SCs.

Iridium(III)-Cp*-(imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenol analogues as hypoxia active, GSH-resistant cancer cytoselective and mitochondria-targeting cancer stem cell therapeutic agents

Herein, we have introduced a series of iridium(III)-Cp*-(imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenol complexes via a convenient synthetic methodology, which act as hypoxia active and glutathione-resistant anticancer metallotherapeutics. The [Ir^III(Cp*)(L5)(Cl)](PF₆) (IrL5) complex exhibited the best cytoselectivity, GSH resistance and hypoxia effectivity in HeLa and Caco-2 cells among the synthesized complexes. IrL5 also exhibited highly cytotoxic effects on the HCT-116 CSC cell line. This complex was localized in the mitochondria and subsequent mitochondrial dysfunction was observed via MMP alteration and ROS generation on colorectal cancer stem cells. Cell cycle analysis also established the potential of this complex in mediating G2/M phase cell cycle arrest.