Methylation of Notch3 modulates chemoresistance via P-glycoprotein

Notch signaling and cancer: Insights into chemoresistance, immune evasion, and immunotherapy

The Notch signaling pathway is a fundamental and highly conserved cell-to-cell communication system vital for embryonic development and tissue maintenance. However, its dysregulation has been associated with the initiation, progression, and chemoresistance of various cancers. In this comprehensive review, we will take an in-depth look at the multiple roles of the Notch family in cancer pathogenesis, immune response, and resistance to chemotherapy. We delve into the complicated mechanisms by which Notch signaling promotes tumor growth and development, including its influence on TME remodeling and immune evasion strategies. We will also be discussing recent studies that shed light on the connection between cancer stemness and chemoresistance mediated through the activation of Notch signaling pathways. Elucidation of the interplay between the Notch pathway and major constituents of the TME, including immune cells and cancer-associated fibroblasts, is necessary for the development of targeted therapies against Notch-driven tumors. We further discuss the potential of targeting Notch signaling alone or in combination with standard chemotherapy and immunotherapy as a potent strategy to overcome chemoresistance and improve patient outcomes. We conclude by discussing the challenges and future prospects of using Notch signaling as a therapeutic target in cancer treatment, focusing on how precision medicine and combination approaches are important.

CRISPR-mediated promoter de/methylation technologies for gene regulation

DNA methylation on cytosines of CpG dinucleotides is well established as a basis of epigenetic regulation in mammalian cells. Since aberrant regulation of DNA methylation in promoters of tumor suppressor genes or proto-oncogenes may contribute to the initiation and progression of various types of human cancer, sequence-specific methylation and demethylation technologies could have great clinical benefit. The CRISPR-Cas9 protein with a guide RNA can target DNA sequences regardless of the methylation status of the target site, making this system superb for precise methylation editing and gene regulation. Targeted methylation-editing technologies employing the dCas9 fusion proteins have been shown to be highly effective in gene regulation without altering the DNA sequence. In this review, we discuss epigenetic alterations in tumorigenesis as well as various dCas9 fusion technologies and their usages in site-specific methylation editing and gene regulation.

Bcl-2 Antiapoptotic Family Proteins and Chemoresistance in Cancer

Cancer is a daunting global problem confronting the world's population. The most frequent therapeutic approaches include surgery, chemotherapy, radiotherapy, and more recently immunotherapy. In the case of chemotherapy, patients ultimately develop resistance to both single and multiple chemotherapeutic agents, which can culminate in metastatic disease which is a major cause of patient death from solid tumors. Chemoresistance, a primary cause of treatment failure, is attributed to multiple factors including decreased drug accumulation, reduced drug-target interactions, increased populations of cancer stem cells, enhanced autophagy activity, and reduced apoptosis in cancer cells. Reprogramming tumor cells to undergo drug-induced apoptosis provides a promising and powerful strategy for treating resistant and recurrent neoplastic diseases. This can be achieved by downregulating dysregulated antiapoptotic factors or activation of proapoptotic factors in tumor cells. A major target of dysregulation in cancer cells that can occur during chemoresistance involves altered expression of Bcl-2 family members. Bcl-2 antiapoptotic molecules (Bcl-2, Bcl-xL, and Mcl-1) are frequently upregulated in acquired chemoresistant cancer cells, which block drug-induced apoptosis. We presently overview the potential role of Bcl-2 antiapoptotic proteins in the development of cancer chemoresistance and overview the clinical approaches that use Bcl-2 inhibitors to restore cell death in chemoresistant and recurrent tumors.

The Notch-3 receptor: A molecular switch to tumorigenesis?

The Notch pathway is a highly conserved pathway increasingly implicated with the progression of human cancers. Of the four existing receptors associated with the pathway, the deregulation in the expression of the Notch-3 receptor is associated with more aggressive disease and poor prognosis. Selective targeting of this receptor has the potential to enhance current anti-cancer treatments. Molecular profiling strategies are increasingly incorporated into clinical decision making. This review aims to evaluate the clinical potential of Notch-3 within this new era of personalised medicine.