Modulation of mTOR and epigenetic pathways as therapeutics in gallbladder cancer

A A, Suchita J, Gacche RN. Cancer metastases: Tailoring the targets

Metastasis is an intricate and formidable pathophysiological process encompassing the dissemination of cancer cells from the primary tumour body to distant organs. It stands as a profound and devastating phenomenon that constitutes the primary driver of cancer-related mortality. Despite great strides of advancements in cancer research and treatment, tailored anti-metastasis therapies are either lacking or have shown limited success, necessitating a deeper understanding of the intrinsic elements driving cancer invasiveness. This comprehensive review presents a contemporary elucidation of pivotal facets within the realm of cancer metastasis, commencing with the intricate processes of homing and invasion. The process of angiogenesis, which supports tumour growth and metastasis, is addressed, along with the pre-metastatic niche, wherein the primary tumour prepares for a favorable microenvironment at distant sites for subsequent metastatic colonization. The landscape of metastasis-related genetic and epigenetic mechanisms, involvement of metastasis genes and metastasis suppressor genes, and microRNAs (miRNA) are also discussed. Furthermore, immune modulators' impact on metastasis and their potential as therapeutic targets are addressed. The interplay between cancer cells and the immune system, including immune evasion mechanisms employed by metastatic cells, is discussed, highlighting the importance of targeting immune modulation in arresting metastatic progression. Finally, this review presents promising treatment opportunities derived from the insights gained into the mechanisms of metastasis. Identifying novel therapeutic targets and developing innovative strategies to disrupt the metastatic cascade holds excellent potential for improving patient outcomes and ultimately reducing cancer-related mortality.

Nutrient-epigenome interactions: Implications for personalized nutrition against aging-associated diseases

Aging is a multifaceted process involving genetic and environmental interactions often resulting in epigenetic changes, potentially leading to aging-related diseases. Various strategies, like dietary interventions and calorie restrictions, have been employed to modify these epigenetic landscapes. A burgeoning field of interest focuses on the role of microbiota in human health, emphasizing system biology and computational approaches. These methods help decipher the intricate interplay between diet and gut microbiota, facilitating the creation of personalized nutrition strategies. In this review, we analysed the mechanisms related to nutritional interventions while highlighting the influence of dietary strategies, like calorie restriction and intermittent fasting, on microbial composition and function. We explore how gut microbiota affects the efficacy of interventions using tools like multi-omics data integration, network analysis, and machine learning. These tools enable us to pinpoint critical regulatory elements and generate individualized models for dietary responses. Lastly, we emphasize the need for a deeper comprehension of nutrient-epigenome interactions and the potential of personalized nutrition informed by individual genetic and epigenetic profiles. As knowledge and technology advance, dietary epigenetics stands on the cusp of reshaping our strategy against aging and related diseases.

ELF3 suppresses gallbladder cancer development through downregulation of the EREG/EGFR/mTOR complex 1 signalling pathway

The prognosis of gallbladder cancer (GBC) remains poor, and a better understanding of GBC molecular mechanisms is important. Genome sequencing of human GBC has demonstrated that loss-of-function mutations of E74-like ETS transcription factor 3 (ELF3) are frequently observed, with ELF3 considered to be a tumour suppressor in GBC. To clarify the underlying molecular mechanisms by which ELF3 suppresses GBC development, we performed in vivo analysis using a combination of autochthonous and allograft mouse models. We first evaluated the clinical significance of ELF3 expression in human GBC tissues and found that low ELF3 expression was associated with advanced clinical stage and deep tumour invasion. For in vivo analysis, we generated Pdx1-Cre; KrasG12D ; Trp53R172H ; Elf3f/f (KPCE) mice and Pdx1-Cre; KrasG12D ; Trp53R172H ; Elf3wt/wt (KPC) mice as a control and analysed their gallbladders histologically. KPCE mice developed larger papillary lesions in the gallbladder than those developed by KPC mice. Organoids established from the gallbladders of KPCE and KPC mice were analysed in vitro. RNA sequencing showed upregulated expression of epiregulin (Ereg) in KPCE organoids, and western blotting revealed that EGFR/mechanical targets of rapamycin complex 1 (mTORC1) were upregulated in KPCE organoids. In addition, ChIP assays on Elf3-overexpressing KPCE organoids showed that ELF3 directly regulated Ereg. Ereg deletion in KPCE organoids (using CRISPR/Cas9) induced EGFR/mTORC1 downregulation, indicating that ELF3 controlled EGFR/mTORC1 activity through regulation of Ereg expression. We also generated allograft mouse models using KPCE and KPC organoids and found that KPCE organoid allograft tumours exhibited poorly differentiated structures with mTORC1 upregulation and mesenchymal phenotype, which were suppressed by Ereg deletion. Furthermore, EGFR/mTORC1 inhibition suppressed cell proliferation and epithelial-mesenchymal transition in KPCE organoids. Our results suggest that ELF3 suppresses GBC development via downregulation of EREG/EGFR/mTORC1 signalling. EGFR/mTORC1 inhibition is a potential therapeutic option for GBC with ELF3 mutation. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

HKI-272 contributes to gemcitabine-mediated anti-proliferative and anti-metastatic effects through EGFR suppression in gallbladder cancer

Gallbladder cancer (GBC) is a rare malignancy of the biliary system and characterized by early metastasis and poor prognosis. To date, no efficient treatment is available for GBC patients. Based on the data from cBioPortal, TIMER, and GDSC, we performed an unbiased screening with 25 candidate compounds that predominantly target ErbB family and identified HKI-272, a highly selective EGFR/ErbB2 inhibitor, displayed decreased IC₅₀ values in three GBC cell lines. HKI-272 not only promoted gemcitabine-mediated anti-proliferative and pro-apoptotic effects and induced cell cycle arrest in GBC, but also enhanced gemcitabine-induced suppressive effects of GBC cell migration and invasion by inhibiting pathways downstream of EGFR. Furthermore, HKI-272, together with gemcitabine, effectively suppressed tumor growth and metastases in mouse models. Immunostaining and HE staining data from both primary tumor and lung metastasis indicated that the anti-proliferative and anti-metastatic effects were mediated through EGFR suppression. Moreover, the expression of EGFR, measured by both immunostaining and HE staining, was correlated with a poor prognosis in GBC. In addition, EGFR in tumor tissues are independent indicators for overall survival in GBC patients. Taken together, our findings suggest that HKI-272 could be a potential therapeutic agent and EGFR might serve as a potential biomarker for patients with GBC.

Cardamonin suppresses pro-tumor function of macrophages by decreasing M2 polarization on ovarian cancer cells via mTOR inhibition

Ovarian cancer is the most fatal tumor characterized by an abundance of tumor-associated macrophage (TAM) infiltrations in women. Functional TAMs, which mainly present M2-like phenotypes and perform key functions on tumor progress, have been considered an attractive target for ovarian cancer therapy. Cardamonin showed an excellent antitumor activity in multiple tumor cells. This study aimed to investigate the role of cardamonin on TAMs. With the conditioned medium of ovarian cancer cells, macrophages were induced to TAMs and, accordingly, promoted the proliferation, migration, and invasion of ovarian cancer cells. Cardamonin suppressed alternatively activated (M2) polarization of TAMs and downregulated TAM-secreted tumorigenic factors, thereby hindering the pro-tumor function of TAMs on ovarian cancer cells. Moreover, cardamonin inhibited tumor growth in xenograft nude mice and lowered the expression of CD163 and CD206. Mechanistically, cardamonin inhibited the phosphorylation of mammalian target of rapamycin (mTOR) and signal transducer and activator of transcription 3 (STAT3), resulting in the suppression of M2 polarization. Furthermore, STAT3 is tightly related with mTOR activity. Altogether, these findings implied that cardamonin suppresses the pro-tumor function of TAMs by decreasing M2 polarization via mTOR inhibition, and cardamonin may be a potential therapeutic agent for ovarian cancer.

DNA methylation in genes associated with the evolution of ageing and disease: A critical review

Ageing is characterised by a physical decline in biological functioning which results in a progressive risk of mortality with time. As a biological phenomenon, it is underpinned by the dysregulation of a myriad of complex processes. Recently, however, ever-increasing evidence has associated epigenetic mechanisms, such as DNA methylation (DNAm) with age-onset pathologies, including cancer, cardiovascular disease, and Alzheimer's disease. These diseases compromise healthspan. Consequently, there is a medical imperative to understand the link between epigenetic ageing, and healthspan. Evolutionary theory provides a unique way to gain new insights into epigenetic ageing and health. This review will: (1) provide a brief overview of the main evolutionary theories of ageing; (2) discuss recent genetic evidence which has revealed alleles that have pleiotropic effects on fitness at different ages in humans; (3) consider the effects of DNAm on pleiotropic alleles, which are associated with age related disease; (4) discuss how age related DNAm changes resonate with the mutation accumulation, disposable soma and programmed theories of ageing; (5) discuss how DNAm changes associated with caloric restriction intersect with the evolution of ageing; and (6) conclude by discussing how evolutionary theory can be used to inform investigations which quantify age-related DNAm changes which are linked to age onset pathology.

Gallbladder Cancer: Current Insights in Genetic Alterations and Their Possible Therapeutic Implications

Due to the fast progression in molecular technologies such as next-generation sequencing, knowledge of genetic alterations in gallbladder cancer (GBC) increases. This systematic review provides an overview of frequently occurring genetic alterations occurring in GBC and their possible therapeutic implications. A literature search was performed utilizing PubMed, EMBASE, Cochrane Library, and Web of Science. Only studies reporting genetic alterations in human GBC were included. In total, data were extracted from 62 articles, describing a total of 3893 GBC samples. Frequently detected genetic alterations (>5% in >5 samples across all studies) in GBC for which targeted therapies are available in other cancer types included mutations in ATM, ERBB2, and PIK3CA, and ERBB2 amplifications. High tumor mutational burden (TMB-H) and microsatellite instability (MSI-H) were infrequently observed in GBC (1.7% and 3.5%, respectively). For solid cancers with TMB-H or MSI-H pembrolizumab is FDA-approved and shows an objective response rates of 50% for TMB-H GBC and 41% for MSI-H biliary tract cancer. Only nine clinical trials evaluated targeted therapies in GBC directed at frequently altered genes (ERBB2, ARID1A, ATM, and KRAS). This underlines the challenges to perform such clinical trials in this rare, heterogeneous cancer type and emphasizes the need for multicenter clinical trials.