Luca Proietti-De-Santis

The serine/threonine kinase AKT is a central node driving cell proliferation, survival and migration, and its hyperactivation promotes cancer progression and chemoresistance. The E3-ubiquitin ligase CSA (Cockayne syndrome group A protein) ubiquitinates a range of substrates to control DNA repair, transcription and cell division; loss-of-function mutations in the CSA gene cause the degenerative disorder Cockayne syndrome, whereas CSA overexpression is found in breast and other cancers. Here we identify CSA as a novel upstream regulator of AKT. We show that CSA binds the pleckstrin-homology (PH) domain of AKT and catalyzes a non-proteolytic, K63-linked polyubiquitination of AKT. This modification promotes the recruitment of AKT to the plasma membrane and its activating phosphorylation on T308 and S473 upon stimulation with either IGF-1 or EGF. In CSA-overexpressing breast cancer cells, CSA silencing impairs AKT ubiquitination and membrane recruitment, blunting its activation resulting in reduced proliferation, clonogenicity and migration of the cells; expression of a constitutively active AKT rescues these defects, placing AKT genetically downstream of CSA. Conversely, re-expression of CSA, in patient-derived CS-A cells, restores AKT phosphorylation and activity. Transcriptomic profiling further shows that CSA depletion phenocopies a coherent, core subset of the AKT-dependent gene-expression program. Collectively, our results suggest that the CSA–AKT axis behaves as a double-edged sword: its hyperactivation supports tumorigenesis, whereas its impairment may contribute to the degenerative and aging features of Cockayne syndrome, highlighting CSA as a potential therapeutic target.

Background/Objectives: Melanoma is the deadliest form of skin cancer. Resistance to alkylating agents such as Temozolomide (TMZ) and Dacarbazine (DTIC) limits their clinical benefit, as these drugs remain palliative options when immunotherapies and targeted treatments fail. CSA/ERCC8 is a key component of transcription-coupled nucleotide excision repair (TC-NER), a pathway responsible for removing UV-induced DNA lesions. In principle, loss of a DNA repair factor would be expected to increase carcinogenesis. However, although CSA loss-of-function causes Cockayne Syndrome (CS), affected patients do not exhibit increased skin cancer incidence, suggesting that CSA impairment promotes apoptosis rather than tumor development. This paradox raises the possibility that CSA inhibition may selectively target melanoma cell survival pathways. Methods: The expression of CSA/ERCC8 was analyzed by qRT-PCR and Western blot. ERCC8 was silenced using antisense oligonucleotides. Cell viability, apoptosis, cell cycle progression, drug sensitivity, and DNA damage were assessed by functional assays, including IC50 determination and Bliss analysis for drug interactions. Results: We identified CSA/ERCC8 as a driver of melanoma chemoresistance. CSA was markedly overexpressed in primary and metastatic melanoma cells. ERCC8 silencing reduced proliferation, induced apoptosis, and significantly enhanced sensitivity to low doses of TMZ and DTIC while sparing normal cells. Conclusions: CSA represents a promising therapeutic target to overcome chemoresistance in melanoma. Its inhibition enhances the efficacy and selectivity of alkylating agents, supporting its potential as a salvage strategy for refractory disease and warranting further preclinical and clinical investigation.

Tyroid hormones ,are key regulators of energy metabolism, involeved in a systemic conversion of T4 to T3. This reaction is catalyzed by selenoprotein iodothyronine deiodinase type 1 (DIO1). DIO1 protein is overexpressed in the liver and kidney tissue and it is regulated by nutritional factor, cytokines and oxidative stress. The present study aimed to explore, in an in vitro model of LPS-induced inflammation, the effects of a combination of selected nutrients—vitamin A, selenium, taurine, oleic acid, and resveratrol—on the expression and activity of DIO1 (Type 1 Iodothyronine Deiodinase) in Hepatoma cancer cells (HEPG2). The objective was to determine whether these bioactive compounds could mitigate inflammation-induced suppression of peripheral thyroid hormone activation, thereby supporting a more favorable redox and metabolic profile.To summarize, simoltaneous treatment with taurine, resveratrol, oleic acid and vitamin A not only prevents DIO-1 suppression, but also positively regulates its levels of expression offering a promising avenue for maintaining endocrine and metabolic health in frail, elderly, or oncologic patients and potentially across a broader spectrum of chronic inflammatory conditions.

Melanoma is the deadliest form of skin cancer, with resistance to alkylating agents such as Temozolomide (TMZ) and Dacarbazine (DTIC) further limiting the efficacy of these drugs, which remain palliative options when modern immunotherapies and targeted therapies fail. Here, we identify the Cockayne Syndrome group A (CSA) protein—a key component of Transcription-Coupled Nucleotide Excision Repair (TC-NER)—as a novel driver of melanoma chemo-resistance. CSA is markedly over-expressed in both primary and metastatic melanoma cells. Silencing CSA using Antisense Oligonucleotides (ASOs) robustly reduces melanoma cell proliferation, induces apoptosis, and—critically—sensitizes cells to low doses of TMZ and DTIC, while sparing normal cells. Notably, although CSA loss-of-function underlies Cockayne Syndrome (CS), a disorder characterized by defective repair of UV-induced DNA damage, these patients do not exhibit an increased incidence of skin cancer. This paradox highlights a unique biological context in which impaired CSA function promotes cellular apoptosis rather than carcinogenesis, suggesting that CSA inhibition could selectively cripple melanoma cells. These findings establish CSA as a promising therapeutic target to overcome chemo-resistance in melanoma. Combining CSA inhibition with alkylating agents offers a potential salvage strategy in patients with refractory disease and warrants further preclinical and clinical investigation.

Parkinson’s disease (PD) is one of the most common neurodegenerative disorders, characterized by an initial and progressive loss of dopaminergic neurons of the substantia nigra pars compacta via a potentially substantial contribution from protein aggregates, the Lewy bodies, mainly composed of α-Synuclein among other factors. Distinguishing symptoms of PD are bradykinesia, muscular rigidity, unstable posture and gait, hypokinetic movement disorder and resting tremor. Currently, there is no cure for PD, and palliative treatments, such as Levodopa administration, are directed to relieve the motor symptoms but induce severe side effects over time. Therefore, there is an urgency for discovering new drugs in order to design more effective therapeutic approaches. The evidence of epigenetic alterations, such as the dysregulation of different miRNAs that may stimulate many aspects of PD pathogenesis, opened a new scenario in the research for a successful treatment. Along this line, a promising strategy for PD treatment comes from the potential exploitation of modified exosomes, which can be loaded with bioactive molecules, such as therapeutic compounds and RNAs, and can allow their delivery to the appropriate location in the brain, overcoming the blood–brain barrier. In this regard, the transfer of miRNAs within Mesenchymal stem cell (MSC)-derived exosomes has yet to demonstrate successful results both in vitro and in vivo. This review, besides providing a systematic overview of both the genetic and epigenetic basis of the disease, aims to explore the exosomes/miRNAs network and its clinical potential for PD treatment.

The serine/threonine kinase Akt modulates the functions of numerous substrates, many of them being involved in cell proliferation and growth, metabolism, angiogenesis, resistance to hypoxia and migration. Akt is frequently deregulated in many types of human cancers, its overexpression or abnormal activation being associated with the increased proliferation and survival of cancer cells. A promising avenue for turning off the functionality of Akt is to either interfere with the K63-linked ubiquitination that is necessary for Akt membrane recruitment and activation or increase the K48-linked polyubiquitination that aims to target Akt to the proteasome for its degradation. Recent evidence indicates that targeting the ubiquitin proteasome system is effective for certain cancer treatments. In this review, the functions and roles of Akt in human cancer will be discussed, with a main focus on molecules and compounds that target various elements of the ubiquitination processes that regulate the activation and inactivation of Akt. Moreover, their possible and attractive implications for cancer therapy will be discussed.

DNA repair genes are critical for preserving genomic stability and it is well established that mutations in DNA repair genes give rise to progeroid diseases due to perturbations in different DNA metabolic activities. Cockayne Syndrome (CS) is an autosomal recessive inheritance caused by inactivating mutations in CSA and CSB genes. This review will primarily focus on the two Cockayne Syndrome proteins, CSA and CSB, primarily known to be involved in Transcription Coupled Repair (TCR). Curiously, dysregulated expression of CS proteins has been shown to exhibit differential health outcomes: lack of CS proteins due to gene mutations invariably leads to complex premature aging phenotypes, while excess of CS proteins is associated with carcinogenesis. Thus it appears that CS genes act as a double-edged sword whose loss or gain of expression leads to premature aging and cancer. Future mechanistic studies on cell and animal models of CS can lead to potential biological targets for interventions in both aging and cancer development processes. Some of these exciting possibilities will be discussed in this review in light of the current literature.

Breast cancer (BC) is the most common cancer with the highest frequency of death among women. BC is highly heterogenic at the genetic, biological, and clinical level. Despite the significant improvements in diagnosis and treatments of BC, the high rate of cancer recurrence and resistance to treatment remains a major challenge in clinical practice. This issue is particularly relevant in Triple-Negative Breast Cancer (TNBC) subtype, for which chemotherapy remains the main standard therapeutic approach. Here, we observed that BC cells, belonging to different subtypes, including the TNBC, display an increased expression of Cockayne Syndrome group A (CSA) protein, which is involved in multiple functions such as DNA repair, transcription, mitochondrial homeostasis, and cell division and that recently was found to confer cell robustness when it is up-regulated. We demonstrated that CSA ablation by AntiSense Oligonucleotides (ASOs) drastically impairs tumorigenicity of BC cells by hampering their survival and proliferative capabilities without damaging normal cells. Moreover, suppression of CSA dramatically sensitizes BC cells to platinum and taxane derivatives, which are commonly used for BC first-line therapy, even at very low doses not harmful to normal cells. Finally, CSA ablation restores drug sensitivity in oxaliplatin-resistant cells. Based on these results, we conclude that CSA might be a very attractive target for the development of more effective anticancer therapies.