Mirko Minini

Obesity is a global epidemic characterized by chronic low-grade inflammation and metabolic dysfunction, with adipose tissue playing a pivotal role in these processes. The mixed lineage kinase domain-like pseudokinase (MLKL) is a critical mediator of necroptosis but also exhibits noncanonical roles in metabolic regulation. This study aimed to investigate the adipocyte-specific functions of MLKL in obesity. Using adipocyte-specific Mlkl knockout (Mlkl ^Adi-KO) mice, we observed reduced susceptibility to high-fat diet (HFD)-induced obesity, enhanced glucose tolerance, and improved insulin sensitivity. Mlkl ^Adi-KO mice showed elevated energy expenditure independent of changes in food intake or locomotor activity, correlating with increased mitochondrial function and reduced lipid accumulation in white adipose tissue (WAT). Transcriptomic analyses of WAT revealed significant modulation of pathways linked to oxidative phosphorylation, inflammation, and lipid metabolism. Furthermore, metabolomic profiling highlighted reductions in TCA cycle intermediates, acylcarnitines, and pro-inflammatory amino acids in Mlkl ^Adi-KO mice under HFD conditions. These findings were accompanied by improved hepatic lipid profiles and decreased steatosis, underscoring systemic benefits of adipocyte-specific Mlkl deletion. Mechanistically, Mlkl deficiency altered adipocyte differentiation. These results position MLKL as a promising therapeutic target for obesity and related metabolic disorders, emphasizing the need for future studies using conditional knockout and overexpression models to explore its cell-specific and noncanonical functions in metabolic regulation.

Background and Aims: Immunotherapy has continued to revolutionize cancer treatment, achieving remarkable progress over the past decade. However, in most solid tumors, its effectiveness is often impaired because of immune resistance driven by the tumor microenvironment (TME). In fibrotic cancers, such as cholangiocarcinoma (CCA), the extracellular matrix (ECM) and cancer-associated fibroblasts (CAFs) form a dense, rigid stroma that hinders immune cell infiltration and promotes immunosuppression. Overcoming these physical and biological barriers is crucial for fully unleashing the potential of immunotherapeutic approaches. Approach and Results: We developed a dual-action strategy combining photothermal therapy (PTT) using gold-decorated iron oxide nanoflowers (GIONFs) and PD-1 immune checkpoint blockade. This approach was evaluated in preclinical models of CCA to assess its impact on ECM remodeling, CAF modulation, immune cell activation, and tumor growth. The combinatorial strategy effectively reduced ECM stiffness, reprogrammed CAF subsets, and enhanced cytotoxic T-cell infiltration. In preclinical CCA models, treated tumors shift from immune-cold to immune-hot states. This combination amplifies antitumor immune responses, decreases immunosuppressive stromal signatures, and improves tumor control. Conclusions: Our findings emphasize the therapeutic potential of combining nanotechnology and immunotherapy to reshape the TME and overcome immunotherapy resistance in fibrotic tumors, such as CCA. Targeting both ECM and immune checkpoints has emerged as a promising and versatile strategy to enhance the efficacy of immunotherapy against desmoplastic cancers.

Intrahepatic cholangiocarcinoma (iCCA) is an agressive tumour from the biliary tree that is characterized by a prominent desmoplastic stroma mainly composed of cancer-associated fibroblasts (CAF) and a poor prognosis due to its late clinical presentation and the lack of effective non-surgical treatments. Current therapies still include chemotherapeutic combinations of gemcitabine and cisplatin for the majority of the patients showing poor results due the apparition of resistance. This situation led us to interrogate the potential role in the development of chemoresistance of ZEB1, an EMT-inducing transcription factor (EMT-TF) that we previously identified as a pro tumorigenic factor in tumour cells and CAF of iCCA. By analysing human CCA samples and sc-RNAseq public databases, we show here that ZEB1 is present in the tumour microenvironment of all iCCA patients tested and is prominently expressed by CAF. Using cellular models of CAF, we show that cells depleted for ZEB1 are more sensitive to gemcitabine and cisplatin, via a mechanism involving the regulation of the anti-apoptotic gene BCL2. Moreover, ZEB1 expressing CAF protect iCCA tumour cells against the toxicity of the chemotherapeutic drugs, an event that could be reversed by a BCL2 inhibitor venetoclax. Therefore, our results point to the use of BCL2 inhibitors to improve the efficacy of current chemotherapeutic regimens of gemcitabine and cisplatin in iCCA patients.

Cholangiocarcinoma (CCA) is a highly aggressive tumor of the biliary tree characterized by an intense desmoplastic tumor microenvironment (TME). To date, treatment of CCA remains challenging; tumor resection is the only curative treatment with a high recurrence probability. Besides resection, therapeutic options have moved forward with the advent of immunotherapies, but these remain limited and low effective. Our knowledge about the cellular interplays in CCA is still fragmentary. An area is currently emerging regarding the potential role of cancer cell plasticity in the genesis of an immunosuppressive microenvironment. The cancer cells’ ability to acquire stemness properties and to disseminate through an epithelial-mesenchymal transition (EMT) shape a tumor immune microenvironment that supports cancer progression by attracting immunosuppressive cells including myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs), M2 macrophages, and by increasing the expression of inhibitory immune checkpoints such as PD-1/PD-L-1. EMT-inducing transcription factors (EMT-TF) have recently emerged as regulators of tumor immunity by creating an immunosuppressive microenvironment. This review delves into the molecular mechanisms underlying the existing links between EMT/stemness and tumor immune microenvironment, as well as the last discoveries in CCA.

During the last decade, immunotherapy has radically changed perspectives on anti-tumor treatments. However, solid tumor treatment by immunotherapy has not met expectations. Indeed, poor clinical response to treatment has highlighted the need to understand and avoid immunotherapy resistance. Cholangiocarcinoma (CCA) is the second cause of hepatic cancer-related deaths because of drug inefficacy and chemo-resistance in a majority of patients. Thus, intense research is ongoing to better understand the mechanisms involved in the chemo-resistance processes. The tumor microenvironment (TME) may be involved in tumor therapy resistance by limiting drug access. Indeed, cells such as cancer-associated fibroblasts (CAFs) alter TME by producing in excess an aberrant extracellular matrix (ECM). Interestingly, CAFs are the dominant stromal component in CCA that secrete large amounts of stiff ECM. Stiff ECM could contribute to immune exclusion by limiting anti-tumor T-cells drop-in. Herein, we summarize features, functions, and interactions among CAFs, tumor-associated ECM, and immune cells in TME. Moreover, we discuss the strategies targeting CAFs and the remodeling of the ECM to improve immunotherapy and drug therapies.

Microbes hijack prostate cancer therapy: Androgens such as testosterone and dihydrotestosterone are essential for male reproduction and sexual function. Androgens can also influence the growth of prostate tumor cells, and androgen deprivation therapy (ADT) either by surgical means (castration) or pharmacological approaches (hormone suppression), is the cornerstone of current prostate cancer treatments. Pernigoni et al . found that when the body was deprived of androgens during ADT, the gut microbiome could produce androgens from androgen precursors (see the Perspective by McCulloch and Trinchieri). Gut commensal microbiota in ADT-treated patients or castrated mice produced androgens that were absorbed into the systemic circulation. These microbe-derived androgens appeared to favor the growth of prostate cancer and helped to facilitate development into a castration- or endocrine therapy–resistant state. —PNK