Regulation of signal transduction pathways in colorectal cancer: implications for therapeutic resistance

Prognostic and predictive impact of NOTCH1 in early breast cancer

PURPOSE

Systemic therapy plays a major part in the cure of patients with early breast cancer (eBC). However, personalized treatment concepts are required to avoid potentially harmful overtreatment. Biomarkers are pivotal for individualized therapy. The Notch signalling pathway is widely considered as a suitable prognostic or predictive marker in eBC. This study aimed primarily at assessing the relationship between NOTCH1 mRNA expression levels and histopathological features of breast cancer tumors, as well as clinical characteristics of the correspondent eBC patients. As a secondary aim, we investigated the prognostic and predictive value of NOTCH1 by assessing possible associations between NOTCH1 mRNA expression and recurrence-free interval (RFI) and overall survival after five years of observation.

PATIENTS AND METHODS

The relative NOTCH1 mRNA expression was determined in 414 tumour samples, using quantitative PCR in a prospective, multicenter cohort (Prognostic Assessment in Routine Application (PiA), 2009-2011, NCT01592825) of 1,270 female eBC patients.

RESULTS

High NOTCH1 mRNA expression was detected in one-third of the tumours and was associated with negative hormone receptor status and high uPA/PAI-1 status. In addition, high NOTCH1 mRNA expression was found to be associated with more RFI related events (adjusted hazard ratio 2.1, 95% CI 1.077-4.118). Patients who received adjuvant chemotherapy and had high NOTCH1 mRNA expression in the tumour (n = 86) were three times more likely to have an RFI event (adjusted hazard ratio 3.1, 95% CI 1.321-7.245, p = 0.009).

CONCLUSION

In this cohort, NOTCH1 mRNA expression had a prognostic and predictive impact. Tumours with high NOTCH1 mRNA expression may be less sensitive to cytotoxic treatment and downregulation of the Notch signalling pathway (e.g. by γ-secretase inhibitors) may be valuable for eBC therapy as an individualised treatment option.

The Role of Tumor Stem Cells in Colorectal Cancer Drug Resistance

Background: Colorectal cancer is a major cause of mortality among the prevalent malignant tumors of the gastrointestinal tract. Although chemotherapy is a standard treatment for colorectal cancer, its efficacy is limited by chemoresistance. Recent studies have investigated targeting tumor stem cells as a potential new therapeutic approach for addressing chemoresistance in colorectal cancer. Colorectal cancer frequently relapses, with tumor stem cells often representing one of the leading causes of treatment failure. Purpose: Understanding drug resistance in colorectal cancer stem cells is crucial for improving treatment outcomes. By focusing on developing targeted therapies that specifically address drug resistance in colorectal cancer stem cells, there is potential to make significant advancements in the treatment of colorectal cancer.This approach may lead to more effective and lasting outcomes in patients battling colorectal cancer. Research Design: In this review, a comprehensive overview of recent research on colorectal cancer stem cell treatment resistance is presented.Results: Elucidating the key underlying mechanisms. This review also highlights the potential benefits of targeted therapies in overcoming colorectal cancer resistance to treatment. Conclusions: CCSCs are key players in drug resistance of CRC, indicating their potential as targets for effective therapy. Elucidating their role in this process could aid in discovering tailored treatment strategies.The significance of signaling pathways, TME, and miRNA in regulating drug resistance in CCSCs is been highlighted.

Synergistic Approach of Antibody-Photosensitizer Conjugate Independent of KRAS-Mutation and Its Downstream Blockade Pathway in Colorectal Cancer

Here, a novel approach is presented to improve the efficacy of antibody-drug conjugates (ADC) by integrating antibody-mediated immunotherapy and photodynamic therapy (PDT) in a combination therapy system utilizing an antibody-photosensitizer conjugate (APC) platform based on a poloxamer polymer linker. To specifically target Kirsten rat sarcoma 2 viral oncogene homolog (KRAS)-mutated cancer cells, an antibody antiepidermal growth factor receptor (EGFR), cetuximab, with a poloxamer linker coupled with the photosensitizer chlorin e6 through click chemistry (cetuximab-maleimide-poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide)-chlorine e6 conjugate, CMPXC) is synthesized. CMPXC is cytotoxic upon laser treatment, achieving a 90% cell death by suppressing KRAS downstream signaling pathways associated with ERK and AKT proteins, confirmed using RNA sequencing analysis. In KRAS-mutated colorectal cancer mouse models, CMPXC significantly enhances antitumor efficacy compared with cetuximab treatment alone, resulting in an 86% reduction in tumor growth. Furthermore, CMPXC treatment leads to a 2.24- and 1.75-fold increase in dendritic and priming cytotoxic T cells, respectively, highlighting the immune-activating potential of this approach. The findings suggest that the APC platform addresses the challenges associated with ADC development and EGFR-targeted therapy, including the synergistic advantages of antibody-mediated immunotherapy and PDT.

Diatom-Based Nanomedicine for Colorectal Cancer Treatment: New Approaches for Old Challenges

Colorectal cancer is among the most prevalent and lethal cancers globally. To address this emergency, countries have developed diffuse screening programs and innovative surgical techniques with a consequent decrease in mortality rates in non-metastatic patients. However, five years after diagnosis, metastatic CRC is still characterized by less than 20% survival. Most patients with metastatic CRC cannot be surgically treated. For them, the only option is treatment with conventional chemotherapies, which cause harmful side effects in normal tissues. In this context, nanomedicine can help traditional medicine overcome its limits. Diatomite nanoparticles (DNPs) are innovative nano-based drug delivery systems derived from the powder of diatom shells. Diatomite is a porous biosilica largely found in many areas of the world and approved by the Food and Drug Administration (FDA) for pharmaceutical and animal feed formulations. Diatomite nanoparticles with a size between 300 and 400 nm were shown to be biocompatible nanocarriers capable of delivering chemotherapeutic agents against specific targets while reducing off-target effects. This review discusses the treatment of colorectal cancer with conventional methods, highlighting the drawbacks of standard medicine and exploring innovative options based on the use of diatomite-based drug delivery systems. Three targeted treatments are considered: anti-angiogenetic drugs, antimetastatic drugs, and immune checkpoint inhibitors.

Triazole-fused pyrimidines in target-based anticancer drug discovery

In recent decades, the development of targeted drugs has featured prominently in the treatment of cancer, which is among the major causes of mortality globally. Triazole-fused pyrimidines, a widely-used class of heterocycles in medicinal chemistry, have attracted considerable interest as potential anticancer agents that target various cancer-associated targets in recent years, demonstrating them as valuable templates for discovering novel anticancer candidates. The current review concentrates on the latest advancements of triazole-pyrimidines as target-based anticancer agents, including works published between 2007 and the present (2007-2022). The structure-activity relationships (SARs) and multiple pathways are also reviewed to shed light on the development of more effective and biotargeted anticancer candidates.

Advances of Wnt Signalling Pathway in Colorectal Cancer

Colorectal cancer (CRC) represents one of the most common cancers worldwide, with a high mortality rate despite the decreasing incidence and new diagnostic and therapeutic strategies. CRC arises from both epidemiologic and molecular backgrounds. In addition to hereditary factor and genetic mutations, the strongly varying incidence of CRC is closely linked to chronic inflammatory disorders of the intestine and terrible dietary habits. The Wnt signalling pathway is a complex regulatory network that is implicated in many CRC physiological processes, including cancer occurrence, development, prognosis, invasion, and metastasis. It is currently believed to include classical Wnt/β-catenin, Wnt/PCP, and Wnt/Ca²⁺. In this review, we summarise the recent mechanisms and potential regulators of the three branches of the Wnt signalling pathway in CRC.

Zinc finger protein 671 has a cancer-inhibiting function in colorectal carcinoma via the deactivation of Notch signaling

Zinc finger protein 671 (ZNF671) has been described as a vital cancer inhibitor in multiple neoplasms, yet the functional roles of ZNF671 in colorectal carcinoma (CRC) remain unresolved. This project examined the possible link between ZNF671 and CRC. Lower levels of ZNF671 were observed in CRC tissue compared with noncancerous tissue, which were related to a worse survival rate in CRC patients. High methylation levels at the ZNF671 gene promoter region were shown in CRC tissue, which were inversely correlated with ZNF671 expression. Treatment with demethylation agents restored ZNF671 levels in CRC cell lines. Up-regulation of ZNF671 resulted in suppressive effects on the proliferative ability and metastatic potency of CRC cells. Moreover, the up-regulation of ZNF671 reinforced the chemosensitivity of CRC cells. A mechanism study determined ZNF671 to be a vital mediator of Notch signaling. The up-regulation of ZNF671 decreased the expression of Notch1 and lowered the levels of NICD, HES1, and HEY1. The overexpression of NICD1 diminished ZNF671-mediated antitumor effects. ZNF671 depletion reinforced Notch signaling, and Notch suppression reversed ZNF671-depletion-elicited protumor effects. Moreover, the overexpression of ZNF671 weakened the tumorigenicity of CRC cells in a xenograft model in vivo. In summary, ZNF671 exerts a cancer-inhibiting function in CRC via the deactivation of Notch signaling. Low ZNF671 levels caused by gene promoter hypermethylation contribute to the malignant transformation of CRC. This work underlines the interest of ZNF671 as a target candidate for exploiting novel anti-CRC therapies.