Intrahepatic cholangiocarcinoma (iCCA) is recognized worldwide as the second leading cause of morbidity and mortality among primary liver cancers, showing a continuously increasing incidence rate in recent years. iCCA aggressiveness is revealed through its rapid and silent intrahepatic expansion and spread through the lymphatic system leading to late diagnosis and poor prognoses. Multi-omics studies have aggregated information derived from single-omics data, providing a more comprehensive understanding of the phenomena being studied. These approaches are gradually becoming powerful tools for investigating the intricate pathobiology of iCCA, facilitating the correlation between molecular signature and phenotypic manifestation. Consequently, preliminary stratifications of iCCA patients have been proposed according to their “omics” features opening the possibility of identifying potential biomarkers for early diagnosis and developing new therapies based on personalized medicine (PM). The focus of this review is to provide new and advanced insight into the molecular pathobiology of the iCCA, starting from single- to the latest multi-omics approaches, paving the way for translating new basic research into therapeutic practices.

Extracellular signal-regulated kinase 1/2 (ERK1/2) is involved in the regulation of the key cellular processes that are essential for the proper functioning of the cell under physiological conditions. Notably, the hyperactivation of ERK1/2 is implicated in oncogenesis and metastatic dissemination across various tumor types, making it an attractive candidate for targeted therapy (TT) through functional inhibition. In intrahepatic cholangiocarcinoma (iCCA), sustained ERK1/2 activation represents one of the major events within the complex signaling network that drives tumor development and progression. In this review, we dissect the biological role of ERK1/2 signaling in iCCA and highlight recent preclinical advances involving selective small-molecule ERK1/2 inhibitors. In vitro and in vivo studies have demonstrated how these inhibitors present effective anti-tumorigenic properties. In particular, PD901 and U0126 effectively reduce iCCA cell proliferation and invasion. Furthermore, Ulixertinib has shown a favorable therapeutic index and encouraging activity in clinical trials involving advanced solid tumors, including iCCA, paving the way for a new therapeutic approach targeting ERK1/2. Nevertheless, the heterogeneous and dynamic molecular landscape of iCCA, often accompanied by drug resistance, presents significant therapeutic challenges. We underscore how targeting the ERK1/2 pathway could represent a cornerstone within a multifaceted therapeutic strategy, fostering the development of personalized treatment approaches and improving clinical outcomes in iCCA patients.

Pigment epithelium-derived factor (PEDF) is a multifunctional soluble glycoprotein, primarily known for its potent anti-angiogenic properties. In recent years, its ability to counteract cell proliferation and motility has generated interest in PEDF as a potential tumor suppressor. In the intrahepatic Cholangiocarcinoma (iCCA), PEDF, Thrombospondin 1 (THBS1), and Thrombospondin 2 (THBS2) are expressed and released into the tumor microenvironment (TME), where they promote lymphangiogenesis at the expense of the neoangiogenic program, aiding the dissemination of cancer cells via lymphatic vessels. Recently, we demonstrated that THBS1 and THBS2 directly affect iCCA cells, exacerbating their malignant behavior, while the direct role of PEDF remains to be elucidated. In this study, through a cell-based assay and molecular analysis, we investigate the direct function of PEDF on two well-established iCCA cell lines. Our results show that PEDF affects cancer cell motility in a paracrine manner, reducing their migratory and invasive capabilities. Notably, our data suggest that the PEDF-induced inhibition of motility in iCCA cells occurs through the MAPK/ERK signaling pathway, as indicated by the reduced phosphorylation of ERK1/2. Overall, this study provides the first evidence of PEDF acting as a tumor suppressor in iCCA.