Ritis K. Shyanti

CD1d is traditionally recognized as an MHC class I-like antigen-presenting molecule involved in lipid antigen presentation to Natural Killer T (NKT) cells. However, emerging paradigms reveal that its expression on malignant epithelial cells directly influences tumor-intrinsic functions, independent of classical immune surveillance. In this webinar, we will explore the evolving role of tumor-cell CD1d in aggressive cancer. The presentation will discuss how aberrant CD1d expression influences key hallmarks of tumor progression, including proliferation, survival, migration, and epithelial-mesenchymal transition (EMT). We will examine mechanistic insights into how tumor-associated CD1d modulates cell plasticity, stemness-associated pathways, and interactions with the tumor microenvironment beyond its canonical role in antigen presentation. Emphasis will be placed on emerging in vitro and translational findings linking CD1d signaling to metastatic behavior and therapeutic resistance. By mapping these precise in vitro processing dynamics, this webinar bridges the gap between basic tumor immunology and translational drug discovery. Ultimately, we will discuss how uncovering these distinct, non-canonical CD1d pathways on cancer cells shifts our therapeutic focus away from broad immune stimulation and toward targeted interventions. Disrupting this intrinsic tumor-cell axis offers a novel, highly sophisticated therapeutic window to halt metastatic progression and overcome immune evasion in aggressive malignancies.

The variety of available therapies for treating TNBC is constrained by the minimal or no expression of receptors such as estrogen (ER), progesterone (PR), and human epidermal growth factor 2 (HER2). However, estrogen receptor β (ER β ) has emerged as a potential therapeutic target for TNBCs. Tamoxifen (TAM) is used as an endocrine therapy against ER‐positive cancer but has minimal impact on ER‐negative cancers like TNBC. Thymoquinone (TQ) is an active natural compound with anticancer properties, as evidenced by a cumulative number of reports. A combinatorial approach to targeting EMT in TNBC is one strategy that may improve TAM activity. In this study, we evaluated the binding affinity and stability of TQ and TAM with ER β in silico and assessed their cytotoxic potential individually and in combination in vitro. Docking and molecular dynamics (MD) studies confirmed interactions between ER β and TQ, TAM, and GEN. The IC ₅₀ values for TQ and TAM were approximately 18.44 and 11.76 μ M, respectively, for MDA‐MB‐468, and 22.06 and 15.73 μ M, respectively, for MDA‐MB‐231. An in vitro study demonstrated enhanced cytotoxic effects when TQ (20 μ M) and TAM (13 μ M) were combined. Further analysis revealed downregulation of the mesenchymal markers CDH2 (N‐cadherin) and vinculin, which are responsible for cell migration. Additionally, low vimentin and enhanced E‐cadherin expression lead to downregulation of core EMT regulators, including SNAIL1 and ZEB1. In conclusion, TQ showed potential chemomodulatory effects on TAM against TNBC by reducing the expression of EMT‐associated markers.

Head and neck cancer squamous cell carcinoma (HNSCC) cells exhibit both structural and functional diversity, making them valuable models for understanding tumor heterogeneity at clinical levels. In this study, we generated single-cell-derived spheroids (SCDS) from HNSCC cell lines and patient tumor cells using scaffold- and non-scaffold-based methods to assess this variability. A distinct structural variability among these SCDS, categorized as hypo- and hyperproliferative spheroids based on size, was observed. Hyperproliferative spheroids demonstrated heightened proliferative and tumorigenic potential and increased sensitivity to cisplatin and radiation, while hypoproliferative spheroids exhibited enhanced migratory capabilities. Single-cell RNA sequencing (scRNA-seq) of hypo- and hyperproliferative spheroids provided insights into the transcriptional landscape of HNSCC cells, validating the observed structural and functional heterogeneities within primary tumors. These functionally and genetically characterized spheroids offer valuable tools for the development of next-generation therapeutics. Statement of Significance Establishment and characterization of single-cell-derived spheroids from head and neck cancer cells, employing scaffold and non-scaffold materials, demonstrate functional and genetic heterogeneity. Single-cell analysis reveals correlations between genetic diversity and spheroid functionality. These characterized spheroids offer potential for advancing therapeutics development.

Berberine has shown anticancer properties and has potential for a chemopreventive and/or chemotherapeutic agent for breast cancer. Berberine showed cytotoxicity to breast cancer cells, with an increase in the levels of p21/cip1 and p27/kip1, cyclin-dependent kinase inhibitors (CDKI), but mechanisms involved in up-regulating these molecules are largely unknown. Herein, we studied the key regulatory mechanisms involved in berberine-mediated up-regulation of p21/cip1 and p27/kip1. Berberine treatment for 24 and 48 h decreased the number of cells by 44–84% (P < 0.0001) and 38–78% (P < 0.0001), and increased cell death by 12–17% (P < 0.005) and 38–78% (P < 0.0001) in MCF-7 and MDA-MB-231 cells, respectively. Cells were arrested in G1 phase by berberine which was accompanied with up-regulation of mRNA and protein level of both p21/cip1 and p27/kip1. Berberine decreased the expression of protein levels of cyclin D1, cyclin E, CDK2, CDK4, and CDK6 to cause G1 phase arrest. Berberine caused nuclear localization of p21/cip1 in both the cell lines. Our data for the first time showed that the post-translational stability of both the proteins was strongly increased by berberine as examined by cycloheximide chase assay. Inhibition of Akt was associated with berberine-mediated up-regulation of p21/cip1 and also led to a decrease in cell viability accompanied with significant G1 phase cell cycle arrest. Our study revealed that berberine not only up-regulates mRNA and protein levels of p21/cip1 and p27/kip1 but also increases their nuclear localization and post-translational protein stability. Further, Akt inhibition was found to mediate berberine-mediated up-regulation of p21/cip1 but not the p27/kip1.