Rodriguez-Santana, C. | bioRxiv Science

bioRxiv2026

GALE-dependent glycoproteome remodelling is a determinant of oncogenic RAS transformation

Oncogenic transformation is accompanied by extensive remodelling of the cellular glycosylation landscape, yet the mechanisms linking oncogenic signalling to glycoproteome reprogramming remain poorly defined. We used site-resolved intact glycoproteomics to systematically map oncogenic RAS-dependent changes across the N- and O-linked glycoproteome. Integrating multiomics profiling with functional approaches, we identify UDP-glucose 4-epimerase (GALE) as a transcriptional target of oncogenic RAS that is induced through MAPK signalling and MYC-dependent transcription. GALE depletion selectively disrupted RAS-dependent glycoproteome remodelling, preferentially impairing sialylation of N-linked glycans and O-linked GalNAc-type glycosylation. Functionally, these glycosylation defects were accompanied by suppressed anchorage-independent growth and reduced in vivo tumorigenicity of KRAS-mutant cells, establishing GALE-dependent nucleotide-sugar interconversion as a requirement for malignant growth. Clinically, GALE expression was elevated in pancreatic ductal adenocarcinoma, wherein KRAS mutations are highly prevalent, and across a broad spectrum of human cancers. Collectively, our findings define a regulatory axis that connects oncogenic signalling to nucleotide-sugar precursor availability and diversification of the cellular glycan repertoire, revealing GALE as a metabolic dependency in RAS-driven cancer.

Cancer Biology↗

bioRxiv2023

Intratumoral injection of melatonin enhances tumor regression in cell line-derived and patient-derived xenografts of head and neck cancer by increasing mitochondrial oxidative stress

Head and neck squamous cell carcinoma present a high mortality rate. Melatonin has been shown to have oncostatic effects in different types of cancers. However, inconsistent results have been reported for in vivo applications. Consequently, an alternative administration route is needed to improve bioavailability and establish the optimal dosage of melatonin for cancer treatment. On the other hand, the use of patient-derived tumor models has transformed the field of drug research because they reflect the heterogeneity of patient tumor tissues. In the present study, we explore mechanisms for increasing melatonin bioavailability in tumors and investigate its potential as an adjuvant to improve the therapeutic efficacy of cisplatin in the setting of both xenotransplanted cell lines and primary human HNSCC. We analyzed the effect of two different formulations of melatonin administered subcutaneously or intratumorally in Cal-27 and SCC-9 xenografts and in patient-derived xenografts. Melatonin effects on tumor mitochondrial metabolism was also evaluated as well as melatonin actions on tumor cell migration. In contrast to the results obtained with the subcutaneous melatonin, intratumoral injection of melatonin drastically inhibited tumor progression in HNSCC-derived xenografts, as well as in patient-derived xenografts. Interestingly, intratumoral injection of melatonin potentiated CDDP effects, decreasing Cal-27 tumor growth. We demonstrated that melatonin increases ROS production and apoptosis in tumors, targeting mitochondria. Melatonin also reduces migration capacities and metastasis markers. These results illustrate the great clinical potential of intratumoral melatonin treatment and encourage a future clinical trial in cancer patients to establish a proper clinical melatonin treatment.

cancer biology↗