Targeted liposomal doxorubicin/ceramides combinations: the importance to assess the nature of drug interaction beyond bulk tumor cells

Novel Strategy of Antibody Affinity Maturation and Enhancement of Nucleolin-Mediated Antibody-Dependent Cellular Cytotoxicity Against Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a clinically aggressive subtype of breast cancer that remains an unmet medical need. Because TNBC cells do not express the most common markers of breast cancers, there is an active search for novel molecular targets in triple-negative tumors. Additionally, this subtype of breast cancer presents strong immunogenic characteristics which have been encouraging the development of immunotherapeutic approaches against the disease. In this context, nucleolin arises as a promising target for immunotherapy against TNBC. Our group has previously developed an anti-nucleolin VHH-Fc antibody capable of eliciting antibody-dependent cellular cytotoxicity (ADCC). Moreover, we constructed and characterized an antibody library, that was screened against nucleolin-overexpressing cells, originating an enriched anti-nucleolin antibody pool. In this work, a strategy to select individual clones from the pool was designed, combining NGS data with 3D modeling. Two antibodies demonstrated a significant 4.4- and 6.1-fold increase in binding to nucleolin-overexpressing and TNBC cells, and an improvement in affinity to the sub-micromolar range (0.19 µM and 83.69 nM). Additionally, an increment in 4.6- and 3.1-fold in ADCC activity against respective cell lines was observed for the M2 antibody clone. Herein, the affinity maturation strategy developed was validated and corroborated a positive, but not proportional, correlation between antibody binding, affinity, and ADCC.

LncRNA Expression Profiles in C6 Ceramide Treatment Reveal lnc_025370 as a Promoter in Canine Mammary Carcinoma CHMp Cells Progression

Canine mammary carcinomas (CMCs) represent the most prevalent form of cancer in female dogs, characterized by a high incidence and mortality rate. C6 ceramide is recognized for its multifaceted anti-cancer properties, yet its specific influence on CMCs remains to be elucidated. Long noncoding RNAs (lncRNAs), now recognized as functional "dark matter" in precision oncology, are particularly intriguing, with 44% of canine lncRNAs exhibiting tissue-specific expression. In this study, we performed a thorough analysis of lncRNA expression profiles to uncover the mechanisms behind C6 ceramide's anti-cancer activity in CHMp cells. Our findings reveal that C6 ceramide notably inhibits the proliferation of CHMp cells. RNA sequencing identified 4522 lncRNAs with expression changes following C6 ceramide treatment, of which 2936 were upregulated and 1586 were downregulated. Further investigation into Lnc_025370 showed that it is predominantly nuclear-localized and is significantly downregulated by C6 ceramide treatment. Functional studies discovered that overexpression of Lnc_025370 enhances the growth and metastatic capabilities of CHMp cells, which is associated with an increase in NRG1, and concurrently diminishes the anti-cancer effectiveness of C6 ceramide in vitro. Mouse xenograft models also showed that Lnc_025370 overexpression promotes tumor growth and Ki67 expression. Together, our results suggest that Lnc_025370 acts as a pivotal target mediator of C6 ceramide's anti-cancer effects, facilitating the malignant progression of CHMp cells.

Novel Thieno [2,3-b]pyridine Anticancer Compound Lowers Cancer Stem Cell Fraction Inducing Shift of Lipid to Glucose Metabolism

Due to the role of cancer stem cells (CSCs) in tumor resistance and glycosphingolipid (GSL) involvement in tumor pathogenesis, we investigated the effect of a newly synthesized compound (3-amino-N-(3-chloro-2-methylphenyl)-5-oxo-5,6,7,8-tetrahydrothieno[2,3-b]quinoline-2-carboxamide 1 on the percentage of CSCs and the expression of six GSLs on CSCs and non-CSCs on breast cancer cell lines (MDA-MB-231 and MCF-7). We also investigated the effect of 1 on the metabolic profile of these cell lines. The MTT assay was used for cytotoxicity determination. Apoptosis and expression of GSLs were assessed by flow cytometry. A GC–MS-coupled system was used for the separation and identification of metabolites. Compound 1 was cytotoxic for both cell lines, and the majority of cells died by treatment-induced apoptosis. The percentage of CSCs was significantly lower in the MDA-MB-231 cell line. Treatment with 1 caused a decrease of CSC IV⁶Neu₅Ac-nLc₄Cer+ MDA-MB-231 cells. In the MCF-7 cell line, the percentage of GalNAc-GM1b+ CSCs was increased, while the expression of Gg₃Cer was decreased in both CSC and non-CSC. Twenty-one metabolites were identified by metabolic profiling. The major impact of the treatment was in glycolysis/gluconeogenesis, pyruvate and inositol metabolism. Compound 1 exhibited higher potency in MBA-MB-231 cells, and it deserves further examination.