Assessing the Therapeutic Impacts of HAMLET and FOLFOX on BRAF-Mutated Colorectal Cancer: A Study of Cancer Cell Survival and Mitochondrial Dynamics In Vitro and Ex Vivo.

Background and Objectives: Colorectal cancer (CRC) is a major global health challenge. The BRAF V600E mutation, found in 8-12% of CRC patients, exacerbates this by conferring poor prognosis and resistance to therapy. Our study focuses on the efficacy of the HAMLET complex, a molecular substance derived from human breast milk, on CRC cell lines and ex vivo biopsies harboring this mutation, given its previously observed selective toxicity to cancer cells. Materials and Methods: we explored the effects of combining HAMLET with the FOLFOX chemotherapy regimen on CRC cell lines and ex vivo models. Key assessments included cell viability, apoptosis/necrosis induction, and mitochondrial function, aiming to understand the mutation-specific resistance or other cellular response mechanisms. Results: HAMLET and FOLFOX alone decreased viability in CRC explants, irrespective of the BRAF mutation status. Notably, their combination yielded a marked decrease in viability, particularly in the BRAF wild-type samples, suggesting a synergistic effect. While HAMLET showed a modest inhibitory effect on mitochondrial respiration across both mutant and wild-type samples, the response varied depending on the mutation status. Significant differences emerged in the responses of the HT-29 and WiDr cell lines to HAMLET, with WiDr cells showing greater resistance, pointing to factors beyond genetic mutations influencing drug responses. A slight synergy between HAMLET and FOLFOX was observed in WiDr cells, independent of the BRAF mutation. The bioenergetic analysis highlighted differences in mitochondrial respiration between HT-29 and WiDr cells, suggesting that bioenergetic profiles could be key in determining cellular responses to HAMLET. Conclusions: We highlight the potential of HAMLET and FOLFOX as a combined therapeutic approach in BRAF wild-type CRC, significantly reducing cancer cell viability. The varied responses in CRC cell lines, especially regarding bioenergetic and mitochondrial factors, emphasize the need for a comprehensive approach considering both genetic and metabolic aspects in CRC treatment strategies.

Association between AHR Expression and Immune Dysregulation in Pancreatic Ductal Adenocarcinoma: Insights from Comprehensive Immune Profiling of Peripheral Blood Mononuclear Cells.

Pancreatic cancer, particularly pancreatic ductal adenocarcinoma (PDAC), has an immune suppressive environment that allows tumour cells to evade the immune system. The aryl-hydrocarbon receptor (AHR) is a transcription factor that can be activated by certain exo/endo ligands, including kynurenine (KYN) and other tryptophan metabolites. Once activated, AHR regulates the expression of various genes involved in immune responses and inflammation. Previous studies have shown that AHR activation in PDAC can have both pro-tumorigenic and anti-tumorigenic effects, depending on the context. It can promote tumour growth and immune evasion by suppressing anti-tumour immune responses or induce anti-tumour effects by enhancing immune cell function. In this study involving 30 PDAC patients and 30 healthy individuals, peripheral blood samples were analysed. PDAC patients were categorized into Low (12 patients) and High/Medium (18 patients) AHR groups based on gene expression in peripheral blood mononuclear cells (PBMCs). The Low AHR group showed distinct immune characteristics, including increased levels of immune-suppressive proteins such as PDL1, as well as alterations in lymphocyte and monocyte subtypes. Functional assays demonstrated changes in phagocytosis, nitric oxide production, and the expression of cytokines IL-1, IL-6, and IL-10. These findings indicate that AHR's expression level has a crucial role in immune dysregulation in PDAC and could be a potential target for early diagnostics and personalised therapeutics.