Linking stemness with colorectal cancer initiation, progression, and therapy

FOXN3 Downregulation in Colorectal Cancer Enhances Tumor Cell Stemness by Promoting EP300-Mediated Epigenetic Upregulation of SOX12

Cancer stemness plays a crucial role in promoting the progression of colorectal cancer (CRC). Forkhead box N3 (FOXN3) is a tumor suppressor protein. Herein, we investigated the role of FOXN3 in the regulation of CRC cell stemness. Cell viability, proliferation, migration, and invasion were assessed utilizing cell counting kit-8 assay, 5-ethynyl-20-deoxyuridine assay, and Transwell assay, respectively. Cell-sphere formation was assessed using a sphere-forming assay. The enrichment of H3K27ac modifications at the SRY-related HMG-box 12 (SOX12) promoter, interactions among FOXN3, SOX12, and E1A binding protein p300 (EP300) were analyzed using chromatin immunoprecipitation or dual luciferase reporter assays. We found that FOXN3 overexpression inhibited CRC cell proliferation, migration, invasion, stemness, and tumor formation in mice by inactivating the Wnt/β-catenin signaling, while these effects of FOXN3 overexpression were reversed by the overexpression of SOX12. Mechanistically, EP300 increased SOX12 expression in CRC cells by promoting H3K27ac enrichment in the SOX12 promoter. In addition, FOXN3 transcriptionally inhibited EP300 expression in CRC cells by binding to the EP300 promoter. As expected, EP300 overexpression weakened the inhibitory effect of FOXN3 overexpression on CRC cell stemness. Collectively, FOXN3 upregulation inhibited CRC cell stemness by suppressing EP300-mediated epigenetic upregulation of SOX12.

Adaptive Plasticity Tumor Cells Modulate MAPK-Targeting Therapy Response in Colorectal Cancer

MAPK pathway inhibitors (MAPKi) are increasingly used in the treatment of advanced colorectal cancer, but often produce short-lived responses in patients. Although acquired resistance by de novo mutations in tumors have been found to reduce response in some patients, additional mechanisms underlying the limited response durability of MAPK targeting therapy remain unknown. Here, we denote new contributory tumor biology and provide insight on the impact of tumor plasticity on therapy response. Analysis of MAPKi treated patients revealed activation of stemness programs and increased ASCL2 expression, which are associated with poor outcomes. Greater ASCL2 with MAPKi treatment was also seen in patient-derived CRC models, independent of driver mutations. We find ASCL2 denotes a distinct cell population, arising from phenotypic plasticity, with a proliferative, stem-like phenotype, and decreased sensitivity to MAPKi therapy, which were named adaptive plasticity tumor (APT) cells. MAPK pathway suppression induces the APT phenotype in cells, resulting in APT cell enrichment in tumors and limiting therapy response in preclinical and clinical data. APT cell depletion improved MAPKi treatment efficacy and extended MAPKi response durability in mice. These findings uncover a cellular program that mitigates the impact of MAPKi therapies and highlights the importance of addressing tumor plasticity to improve clinical outcomes.

Multiomics approach towards characterization of tumor cell plasticity and its significance in precision and personalized medicine

Cellular plasticity refers to the ability of cells to change their identity or behavior, which can be advantageous in some cases (e.g., tissue regeneration) but detrimental in others (e.g., cancer metastasis). With a better understanding of cellular plasticity, the complexity of cancer cells, their heterogeneity, and their role in metastasis is being unraveled. The plasticity of the cells could also prove as a nemesis to their characterization. In this review, we have attempted to highlight the possibilities and benefits of using multiomics approach in characterizing the plastic nature of cancer cells. There is a need to integrate fragmented evidence at different levels of cellular organization (DNA, RNA, protein, metabolite, epigenetics, etc.) to facilitate the characterization of different forms of plasticity and cell types. We have discussed the role of cellular plasticity in generating intra-tumor heterogeneity. Different omics level evidence is being provided to highlight the variety of molecular determinants discovered using different techniques. Attempts have been made to integrate some of this information to provide a quantitative assessment and scoring of the plastic nature of the cells. However, there is a huge gap in our understanding of mechanisms that lead to the observed heterogeneity. Understanding of these mechanism(s) is necessary for finding targets for early detection and effective therapeutic interventions in metastasis. Targeting cellular plasticity is akin to neutralizing a moving target. Along with the advancements in precision and personalized medicine, these efforts may translate into better clinical outcomes for cancer patients, especially in metastatic stages.

The E3 ubiquitin ligase SCF (FBXW10)-mediated LATS2 degradation regulates angiogenesis and liver metastasis in colorectal cancer

F-box and WD repeat domain containing 10 (FBXW10) is a member of the FBXW subgroup that contains the WD40 domain. FBXW10 has been rarely reported in colorectal cancer (CRC) and its mechanism is unclear. To investigate the role of FBXW10 in CRC, we conducted in vitro and in vivo experiments. Through the database and our clinical samples, we found that FBXW10 expression was up-regulated in CRC, and it was positively correlated with CD31 expression. CRC patients with high FBXW10 expression levels had a poor prognosis. Overexpression of FBXW10 up-regulated cell proliferation, migration and vascular formation, while knockdown of FBXW10 had the opposite effects. Studies on the mechanism of FBXW10 in CRC showed that FBXW10 could ubiquitinate large tumor suppressor kinase 2 (LATS2) and promote its degradation with the Fbox region of FBXW10 played an essential role in this process. In vivo studies demonstrated that knockout of FBXW10 inhibited tumor proliferation and reduced liver metastasis. In conclusion, our study proved that FBXW10 was significantly overexpressed in CRC and was involved in the pathogenesis of CRC by affecting angiogenesis and liver metastasis. Mechanistically, FBXW10 degraded LATS2 through ubiquitination. Therefore, FBXW10-LATS2 can be used as a therapeutic target for CRC in subsequent studies.

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.

Extracellular vesicles: General features and usefulness in diagnosis and therapeutic management of colorectal cancer

In the world, among all type of cancers, colorectal cancer (CRC) is the third most commonly diagnosed in males and the second in females. In most of cases, (RP1) patients’ prognosis limitation with malignant tumors can be attributed to delayed diagnosis of the disease. Identification of patients with early-stage disease leads to more effective therapeutic interventions. Therefore, new screening methods and further innovative treatment approaches are mandatory as they may lead to an increase in progression-free and overall survival rates. For the last decade, the interest in extracellular vesicles (EVs) research has exponentially increased as EVs generation appears to be a universal feature of every cell that is strongly involved in many mechanisms of cell-cell communication either in physiological or pathological situations. EVs can cargo biomolecules, such as lipids, proteins, nucleic acids and generate transmission signal through the intercellular transfer of their content. By this mechanism, tumor cells can recruit and modify the adjacent and systemic microenvironment to support further invasion and dissemination. This review intends to cover the most recent literature on the role of EVs production in colorectal normal and cancer tissues. Specific attention is paid to the use of EVs for early CRC diagnosis, follow-up, and prognosis as EVs have come into the spotlight of research as a high potential source of ‘liquid biopsies’. The use of EVs as new targets or nanovectors as drug delivery systems for CRC therapy is also summarized.

Recent Updates on Mechanisms of Resistance to 5-Fluorouracil and Reversal Strategies in Colon Cancer Treatment

5-Fluorouracil (5-FU) plus leucovorin (LV) remain as the mainstay standard adjuvant chemotherapy treatment for early stage colon cancer, and the preferred first-line option for metastatic colon cancer patients in combination with oxaliplatin in FOLFOX, or irinotecan in FOLFIRI regimens. Despite treatment success to a certain extent, the incidence of chemotherapy failure attributed to chemotherapy resistance is still reported in many patients. This resistance, which can be defined by tumor tolerance against chemotherapy, either intrinsic or acquired, is primarily driven by the dysregulation of various components in distinct pathways. In recent years, it has been established that the incidence of 5-FU resistance, akin to multidrug resistance, can be attributed to the alterations in drug transport, evasion of apoptosis, changes in the cell cycle and DNA-damage repair machinery, regulation of autophagy, epithelial-to-mesenchymal transition, cancer stem cell involvement, tumor microenvironment interactions, miRNA dysregulations, epigenetic alterations, as well as redox imbalances. Certain resistance mechanisms that are 5-FU-specific have also been ascertained to include the upregulation of thymidylate synthase, dihydropyrimidine dehydrogenase, methylenetetrahydrofolate reductase, and the downregulation of thymidine phosphorylase. Indeed, the successful modulation of these mechanisms have been the game plan of numerous studies that had employed small molecule inhibitors, plant-based small molecules, and non-coding RNA regulators to effectively reverse 5-FU resistance in colon cancer cells. It is hoped that these studies would provide fundamental knowledge to further our understanding prior developing novel drugs in the near future that would synergistically work with 5-FU to potentiate its antitumor effects and improve the patient's overall survival.

Emerging Regulatory Mechanisms Involved in Liver Cancer Stem Cell Properties in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the predominant form of primary liver cancer and one of the leading causes of cancer-related deaths worldwide. A growing body of evidence supports the hypothesis that HCC is driven by a population of cells called liver cancer stem cells (LCSCs). LCSCs have been proposed to contribute to malignant HCC progression, including promoting tumor occurrence and growth, mediating tumor metastasis, and treatment resistance, but the regulatory mechanism of LCSCs in HCC remains unclear. Understanding the signaling pathways responsible for LCSC maintenance and survival may provide opportunities to improve patient outcomes. Here, we review the current literature about the origin of LCSCs and the niche composition, describe the current evidence of signaling pathways that mediate LCSC stemness, then highlight several mechanisms that modulate LCSC properties in HCC progression, and finally, summarize the new developments in therapeutic strategies targeting LCSCs markers and regulatory pathways.

Portrait of Cancer Stem Cells on Colorectal Cancer: Molecular Biomarkers, Signaling Pathways and miRNAome

Colorectal cancer (CRC) is a leading cause of cancer death worldwide, and about 20% is metastatic at diagnosis and untreatable. Increasing evidence suggests that the heterogeneous nature of CRC is related to colorectal cancer stem cells (CCSCs), a small cells population with stemness behaviors and responsible for tumor progression, recurrence, and therapy resistance. Growing knowledge of stem cells (SCs) biology has rapidly improved uncovering the molecular mechanisms and possible crosstalk/feedback loops between signaling pathways that directly influence intestinal homeostasis and tumorigenesis. The generation of CCSCs is probably connected to genetic changes in members of signaling pathways, which control self-renewal and pluripotency in SCs and then establish function and phenotype of CCSCs. Particularly, various deregulated CCSC-related miRNAs have been reported to modulate stemness features, controlling CCSCs functions such as regulation of cell cycle genes expression, epithelial-mesenchymal transition, metastasization, and drug-resistance mechanisms. Primarily, CCSC-related miRNAs work by regulating mainly signal pathways known to be involved in CCSCs biology. This review intends to summarize the epigenetic findings linked to miRNAome in the maintenance and regulation of CCSCs, including their relationships with different signaling pathways, which should help to identify specific diagnostic, prognostic, and predictive biomarkers for CRC, but also develop innovative CCSCs-targeted therapies.

Therapeutic targeting of the oncogenic Wnt signaling pathway for treating colorectal cancer and other colonic disorders

The canonical Wnt pathway is one of the key cellular signaling cascades that regulates, via the transcriptional co-activator β-catenin, numerous embryogenic developmental processes, as well as tissue homeostasis. It is therefore not surprising that misregulation of the Wnt/β-catenin pathway has been implicated in carcinogenesis. Aberrant Wnt signaling has been reported in a variety of malignancies, and its role in both hereditary and sporadic colorectal cancer (CRC), has been the subject of intensive study. Interestingly, the vast majority of colorectal tumors harbor mutations in the tumor suppressor gene adenomatous polyposis coli (APC). The Wnt pathway is complex, and despite decades of research, the mechanisms that underlie its functions are not completely known. Thus, although the Wnt cascade is an attractive target for therapeutic intervention against CRC, one of the malignancies with the highest morbidity and mortality rates, achieving efficacy and safety is yet extremely challenging. Here, we review the current knowledge of the Wnt different epistatic signaling components and the mechanism/s by which the signal is transduced in both health and disease, focusing on CRC. We address some of the important questions in the field and describe various therapeutic strategies designed to combat unregulated Wnt signaling, the development of targeted therapy approaches and the emerging challenges that are associated with these advanced methods.

Rat Bone Marrow-Derived Mesenchymal Stem Cells Promote the Migration and Invasion of Colorectal Cancer Stem Cells

Background

Colorectal cancer is one of the most common cancers and the second leading cause of cancer-related deaths worldwide. Targeting cancer stem cells (CSCs) may be a novel strategy for the treatment of colorectal cancer. Previous studies have shown that bone marrow-derived MSCs (BM-MSCs) promote tumor growth and metastasis. However, the role of rat BM-MSCs in the biological behaviors of colorectal CSCs remains unclear until now.

Materials and Methods

BM-MSCs were isolated from rats and characterized. CSCs were enriched from HCT116 cells using the microsphere culture method, and the microspheres incubated for at least 10 passages were termed HCT116-CSCs that were characterized. The effects of rat BM-MSCs on migration and invasion of HCT116-CSCs were examined using transwell migration and invasion assays and xenograft tumor growth assay.

Results

Rat BM-MSCs appeared typical stem cell morphology. Flow cytometry revealed positive CD29 and CD44 expression in rat BM-MSCs at passage 3, and rat BM-MSCs were found to differentiate into osteocytes following incubation in osteogenic induction medium. Microscopy, flow cytometric detection of stem cell surface markers, colony-formation assay and transwell migration and invasion assays characterized the successful preparation of HCT116-CSCs, and subcutaneous injection of HCT116-CSCs produced xenograft tumors in nude mice, while HE staining of the xenograft tumors displayed cancer specimen shapes. Transwell migration and invasion assays showed that rat BM-MSCs promoted the migration and invasion of HCT116-CSCs, and injection of rat BM-MSCs was found to promote the growth of the mouse xenograft tumor derived from HCT116-CSCs.

Conclusion

Rat BM-MSCs promote the migration and invasion of colorectal CSCs, and colorectal CSCs may be a potential target for the therapy against colorectal cancer.

Ovarian Cancer, Cancer Stem Cells and Current Treatment Strategies: A Potential Role of Magmas in the Current Treatment Methods

Epithelial ovarian cancer (EOC) constitutes 90% of ovarian cancers (OC) and is the eighth most common cause of cancer-related death in women. The cancer histologically and genetically is very complex having a high degree of tumour heterogeneity. The pathogenic variability in OC causes significant impediments in effectively treating patients, resulting in a dismal prognosis. Disease progression is predominantly influenced by the peritoneal tumour microenvironment rather than properties of the tumor and is the major contributor to prognosis. Standard treatment of OC patients consists of debulking surgery, followed by chemotherapy, which in most cases end in recurrent chemoresistant disease. This review discusses the different origins of high-grade serous ovarian cancer (HGSOC), the major sub-type of EOC. Tumour heterogeneity, genetic/epigenetic changes, and cancer stem cells (CSC) in facilitating HGSOC progression and their contribution in the circumvention of therapy treatments are included. Several new treatment strategies are discussed including our preliminary proof of concept study describing the role of mitochondria-associated granulocyte macrophage colony-stimulating factor signaling protein (Magmas) in HGSOC and its unique potential role in chemotherapy-resistant disease.

CUL4B contributes to cancer stemness by repressing tumor suppressor miR34a in colorectal cancer

Given that colorectal cancer stem cells (CCSCs) play key roles in the tumor dormancy, metastasis, and relapse, targeting CCSCs is a promising strategy in cancer therapy. Here, we aimed to identify the new regulators of CCSCs and found that Cullin 4B (CUL4B), which possesses oncogenic properties in multiple solid tumors, drives the development and metastasis of colon cancer by sustaining cancer stem-like features. Elevated expression of CUL4B was confirmed in colon tumors and was associated with poor overall survival. Inhibition of CUL4B in cancer cell lines and patient-derived tumor organoids led to reduced sphere formation, proliferation and metastasis capacity. Mechanistically, CUL4B coordinates with PRC2 complex to repress miR34a expression, thus upregulates oncogenes including MYCN and NOTCH1, which are targeted by miR34a. Furthermore, we found that elevated CUL4B expression is associated with miR34a downregulation and upregulation of miR34a target genes in colon cancer specimens. Collectively, our findings demonstrate that CUL4B functions to repress miR34a in maintaining cancer stemness in CRC and provides a potential therapeutic target.