FHOD1 and FMNL1 formin proteins in intestinal gastric cancer: correlation with tumor-infiltrating T lymphocytes and molecular subtypes

Role of FHOD1 in tumor cells and tumor immune microenvironment

FHOD 1 (Formin homology 2 domain containing protein 1) is a member of Diaphanous-related formins (DRFs) which contains a GTP-binding domain (GBD), formin homology (FH) 1 and FH 2 domains, a coiled-coil, and a diaphanous-like autoregulatory domain. Studies have shown that FHOD1 can not only regulate intracellular signals in tumor cells but also regulate various components of the tumor microenvironment (TME), such as T cells, B cells, cancer-associated fibroblasts (CAFs), some cytokines. Aberrant expression and dysfunction of the FHOD1 protein play a key role in tumor immunosuppression. Specifically, FHOD1 can impair function of chemokine receptors that are supposed to direct immune cells to localize to the tumor site accurately. As a result of this impairment, immune cells cannot migrate efficiently into TME, thereby impairing their ability to attack tumor cells. In addition, FHOD1 activated signaling pathways within the immune cells abnormally, resulting in their inability to recognize and destroy tumor cells effectively. Therefore, FHOD1 ultimately leads to a state of immunosuppression in TME, providing favorable conditions for the growth and spread of tumor cells. Altogether this review provides an in-depth understanding of the role of FHOD1 in tumor immunosuppression.

The role of Golgi complex proteins in cell division and consequences of their dysregulation

The GC (Golgi complex) plays a pivotal role in the trafficking and sorting of proteins and lipids until they reach their final destination. Additionally, the GC acts as a signalling hub to regulate a multitude of cellular processes, including cell polarity, motility, apoptosis, DNA repair and cell division. In light of these crucial roles, the GC has garnered increasing attention, particularly given the evidence that a dysregulation of GC-regulated signalling pathways may contribute to the onset of various pathological conditions. This review examines the functions of the GC and GC-localised proteins in regulating cell cycle progression, in both mitosis and meiosis. It reviews the involvement of GC-resident proteins in the formation and orientation of the spindle during cell division. In light of the roles played by the GC in controlling cell division, this review also addresses the involvement of the GC in cancer development. Furthermore, TCGA (The Cancer Genome Atlas) database has been queried in order to retrieve information on the genetic alterations and the correlation between the expression of GC-localised proteins and the survival of cancer patients. The data presented in this review highlight the relevance of the GC in regulating cell cycle progression, cellular differentiation and tumourigenesis.

Formin protein DIAPH1 positively regulates PD-L1 expression and predicts the therapeutic response to anti-PD-1/PD-L1 immunotherapy

Formins are evolutionarily conserved genes and profoundly affect cancer progression. This study aims to explore the expressions, prognostic values, and immunological correlations of Formins in cancer. Specific Formins were dysregulated and immuno-biologically correlated in breast cancer (BRCA). Formins showed different expression patterns, namely some were enriched in immune cells while some were enriched in tumor cells. Among all Formins, DIAPH1 was enriched in tumor cells and associated with an inflamed tumor microenvironment (TME). DIAPH1 functioned as an oncogene in BRCA and mediated TGF-β1-induced epithelial-mesenchymal transformation (EMT) and PD-L1 expression. Moreover, DIAPH1 was overexpressed in most cancers and functioned as a novel pan-cancer immuno-marker, which could predict the response to anti-PD-1/PD-L1 immunotherapy. Overall, DIAPH1 functions as an oncogene and is immunologically correlated, which could be utilized as an alternative biomarker for predicting the immunotherapeutic response.

Formins in Human Disease

Almost 25 years have passed since a mutation of a formin gene, DIAPH1, was identified as being responsible for a human inherited disorder: a form of sensorineural hearing loss. Since then, our knowledge of the links between formins and disease has deepened considerably. Mutations of DIAPH1 and six other formin genes (DAAM2, DIAPH2, DIAPH3, FMN2, INF2 and FHOD3) have been identified as the genetic cause of a variety of inherited human disorders, including intellectual disability, renal disease, peripheral neuropathy, thrombocytopenia, primary ovarian insufficiency, hearing loss and cardiomyopathy. In addition, alterations in formin genes have been associated with a variety of pathological conditions, including developmental defects affecting the heart, nervous system and kidney, aging-related diseases, and cancer. This review summarizes the most recent discoveries about the involvement of formin alterations in monogenic disorders and other human pathological conditions, especially cancer, with which they have been associated. In vitro results and experiments in modified animal models are discussed. Finally, we outline the directions for future research in this field.