Lineage plasticity is recognized as a critical determinant of lethality and resistance to AR pathway inhibitors in prostate cancer. Lineage plasticity is a continuum, ranging from AR activity-low tumors, AR-null tumors that do not express a neuroendocrine prostate cancer (NEPC) program (i.e., double-negative prostate cancer [DNPC]), and AR-null NEPC tumors. Factors upregulated early in lineage plasticity are not well-characterized. The clarification of such factors is essential to identify tumors undergoing lineage plasticity or at risk of this occurring. Our integrative analysis of metastatic prostate cancer patient tumors, patient-derived xenografts, and cell models determined that PROX1 is upregulated early in the lineage plasticity continuum and progressively increases as tumors lose AR activity. We determined DNA methylation is a key regulator of PROX1 expression. PROX1 suppression in DNPC and NEPC reduces cell survival and impacts apoptosis and differentiation, demonstrating PROX1's functional importance. PROX1 is not directly targetable with standard drug development approaches. However, affinity immunopurification demonstrated histone deacetylases (HDACs) are among the top PROX1-interacting proteins; HDAC inhibition depletes PROX1 and recapitulates PROX1 suppression in DNPC and NEPC. Altogether, our results suggest PROX1 promotes the emergence of lineage plasticity, and HDAC inhibition is a promising approach to treat tumors across the lineage plasticity continuum.

Immune evasion is a characteristic hallmark of cancer. Immunotherapies aim to activate and support the body's immune system to recognize and fight tumor cells. Induction of immunogenic cell death (ICD) and the associated activation of danger signaling pathways can increase the immunogenicity of tumor cells. Therapeutic ICD stimuli activate endoplasmic reticulum stress pathways and apoptosis leading to the cellular expression of damage-associated molecular patterns (DAMPs). The aim of our in vitro study was to investigate whether mistletoe extracts induce characteristics of immunogenic tumor cell death in cancer cell lines.
Three human breast cancer cell lines and one murine melanoma cell line (SKBR3, MDA-MB-231, MCF-7, and B16F10) were treated with aqueous, fermented Viscum album extract (VAE: Iscador Qu spec.) and taxol or tunicamycin as positive controls, respectively. To investigate whether VAE induces ribotoxic stress, we measured the ER stress regulators p-eIF2a, ATF4, and CHOP by Western blot. Cell surface exposure of DAMPs (calreticulin, heat shock proteins hsp70 and hsp90), apoptosis and induction of mitochondrial reactive oxygen species (ROS) were assessed by flow cytometry. HMGB1 and ATP were quantified by ELISA and chemiluminescence assay, respectively.
Treatment with VAE resulted in phosphorylation of eIF2α in all cancer cell lines tested and increased calreticulin (CRT) exposure on the surface of pre-apoptotic SKBR3 breast cancer and B16F10 mouse melanoma cells. VAE exerted a concentration-dependent effect in all cell lines, resulting in a significantly increased exposure of three DAMPs (CRT, hsp70 and hsp90) on the surface of early apoptotic cells. Furthermore, VAE elevated mitochondrial ROS production and the release of ATP. HMGB1 release was not induced by VAE.
In this in vitro study, we demonstrated for the first time the potential of a mistletoe extract to induce surrogate markers of immunogenic cancer cell death. This is a primary step in investigating the potential of VAEs to contribute to ICD-induced tumor-specific immune activation.
© 2025. The Author(s).

The extent of mitochondrial heterogeneity and the presence of mitochondrial archetypes in cancer remain unknown. Mitochondria play a central role in the metabolic reprogramming that occurs in cancer cells. This process adjusts the activity of metabolic pathways to support growth, proliferation, and survival of cancer cells. Using a panel of colorectal cancer (CRC) cell lines, we revealed extensive differences in their mitochondrial composition, suggesting functional specialisation of these organelles. We differentiated bioenergetic and mitochondrial phenotypes, which point to different strategies used by CRC cells to maintain their sustainability. Moreover, the efficacy of various treatments targeting metabolic pathways was dependent on the respiration and glycolysis levels of cancer cells. Furthermore, we identified metabolites associated with both bioenergetic profiles and cell responses to treatments. The levels of these molecules can be used to predict the therapeutic efficacy of anti-cancer drugs and identify metabolic vulnerabilities of CRC. Our study indicates that the efficacy of CRC therapies is closely linked to mitochondrial status and cellular bioenergetics.
© 2025. The Author(s).

Endometrial cancer (EC) patients with Diabetes Mellitus (DM) always have a poor prognosis. Estrogen-related receptor α (ERRα) is known as the metabolic-related prognostic factor for EC. However, the mechanism linking glycolipid metabolism dysfunction mediated by ERRα to poor prognosis of EC with DM is still unclear. In vitro, high-glucose (HG) levels showed enhancement of ERRα expression, cell proliferation, and inhibition of the autophagic lysosomes and apoptosis by flow cytometry analysis, transmission electron microscopy, and CCK-8 assays. Mechanistically, lose-and-gain function assay, DNA sequencing, and CO-IP revealed HG increased ERRα expression to promote the transcription of HK2 and HMGCS1, which were the key rate-limiting enzyme of glycolysis-cholesterol synthesis and their metabolites suppressed the autophagy-lysosomal pathway in an ERRα-dependent manner. Furthermore, CO-IP and molecular dynamics simulation uncovered the protein residues (ARG 769HK2 vs. ARG 313HMGCS1) of HK2 and HMGCS1 could bind to p62 to form stable protein complexes involved in the autophagy-lysosomal pathway. In EC tissue from patients with comorbid DM, ERRα was significantly higher expressed compared to EC tissue from patients without evidence for DM (p < 0.05). The 3D EC organoid model with HG stimulation showed that the cell viability of XCT790 + carboplatin treatment was similar to that of metformin+carboplatin treatment, while the obviously bigger volume of organoids was more visible in the metformin+carboplatin group, indicating the therapy of XCT790 + carboplatin had the better inhibition of EC organoids with the same carboplatin dose. Besides insights into the interaction of HG and the autophagy-lysosomal pathway via ERRα, our present study points out the potential benefit of targeting ERRα in patients with EC with dysregulation of glucose and cholesterol metabolism.
© 2025. The Author(s).

Two new Ru(II) complexes, mononuclear [RuCl2(η6-p-cymene)(3,4-dmph-κN)] (1) and the binuclear complex [{RuCl(η6-p-cymene)}2(μ-Cl)(μ-3,4-dmph-κ2N,N')]Cl (2; 3,4-dmph = 3,4-dimethylphenylhydrazine), are synthesized and experimentally and theoretically structurally characterized utilizing 1H and 13C NMR and FTIR spectroscopy, as well as DFT calculations. Degradation product of 2, thus ([{RuCl(η6-p-cymene)}2(μ-Cl)(μ-3,4-dmph-κ2N,N')][RuCl3(η6-p-cymene)] (2b) was characterized with SC-XRD. In the crystals of 2b, the cationic and anionic parts interact through N-H...Cl hydrogen bridges. The spectrofluorimetric measurements proved the spontaneity of the binding processes of both complexes and HSA. Spin probing EPR measurements implied that 1 and 2 decreased the amount of bound 16-doxylstearate and implicated their potential to bind to HSA more strongly than the spin probe. The cytotoxicity assessment of both complexes against the MDA-MB-231 and MIA PaCa-2 cancer cell lines demonstrated a clear dose-dependent decrease in cell viability and no effect on healthy HS-5 cells. Determination of the malondialdehyde and protein carbonyl concentrations indicated that new complexes could offer protective antioxidant benefits in specific cancer contexts. Gel electrophoresis measurements showed the reduction in MMP9 activity and indicated the potential of 1 in limiting the cancer cells' invasion. The annexin V/PI apoptotic assay results showed that 1 and 2 exhibit different selectivity towards MIA PaCa-2 and MDA-MB-231 cancer cells. A comparative molecular docking analysis of protein binding, specifically targeting acetylcholinesterase (ACHE), matrix metalloproteinase-9 (MMP-9), and human serum albumin (HSA), demonstrated distinct binding interactions for each complex.