Exploring the Multi-Faceted Role of Sirtuins in Glioblastoma Pathogenesis and Targeting Options.

Recent advances in glioblastoma (GB) research have shed light on the molecular characteristics, the defected intracellular signaling pathways, and the genetic and epigenetic alterations involved in their pathogenesis. Despite constant efforts, GB remains an aggressive malignant tumor with limited therapeutic approaches, poor prognosis, and a low survival rate. Emerging evidence points towards the crucial impact of epigenetic post-translational modifications in cancer development with emphasis on the regulatory role of histone deacetylation in several key cellular processes, including metabolic pathways, regulation of stress response, senescence, proliferation, DNA repair, and apoptosis. The silent information regulator proteins (Sirtuins) are deacetylases of histone and non-histone proteins that have been recently implicated in the initiation as well as in the progression of GB. Herein, we provide a critical overview of the emerging functional role and mechanism of action of the seven Sirtuins (SIRT1-7) in GB and discuss their potential targeting options in clinical practice.

Treatment with abiraterone or enzalutamide does not impair immunological response to COVID-19 vaccination in prostate cancer patients.

Data regarding the safety and efficacy of COVID-10 vaccines among cancer patients are lacking. Factors such as age, underlying disease and antineoplastic treatment confer negatively to the immune response due to vaccination. The degree of immunosuppression though may be lessen by targeted treatments like the androgen receptor-targeted agents (ARTA) that are commonly used in patients with metastatic prostate cancer. Herein, we report our data on 25 patients with prostate cancer under treatment with ARTA who were vaccinated for COVID-19. Our data suggest that these patients develop neutralizing antibodies against SARS-CoV-2 similarly to healthy volunteers. No safety issues were noted.

BRCA1/2 Mutation Types Do Not Affect Prognosis in Ovarian Cancer Patients.

BACKGROUND: High grade serous ovarian carcinoma (HGSOC) is the most lethal type of epithelial ovarian cancer, with a prevalence of germline BRCA1/2 mutations as high as 20%. Our objective is to determine whether the location of mutations in the different domains of the BRCA1/2 genes affects the clinical outcome of HGSOC patients. METHODS: A total of 51 women with BRCA1 or BRCA2 mutated ovarian cancer were identified. Progression-free survival (PFS) and overall survival (OS) were analyzed. RESULTS: In our study cohort, 35 patients were carriers of germline mutations in BRCA1 and 16 in BRCA2. The median PFS time following completion of the primary therapy was 23.8 months (95% CI 20.1-27.5) and the median OS was 92.9 months (95% CI 69.8-116.1) in all BRCA carriers. After multivariate analysis, no significant association among the location or type of BRCA1/2 mutation with PFS or OS was identified. Notably, significant differences in PFS between carriers of identical mutations in the same BRCA gene were detected. CONCLUSIONS: Among HGSOC patients, BRCA1/2 carriers with mutations in different locations of the genes show no significant difference in survival outcomes, in terms of PFS and OS, suggesting the potential effect of other genetic abnormalities and co-contributing risk factors.

Immunological Response to COVID-19 Vaccination in Ovarian Cancer Patients Receiving PARP Inhibitors.

OBJECTIVE: Vaccination for SARS-CoV-2 provides significant protection against the infection in the general population. However, limited data exist for cancer patients under systemic therapy. METHODS: In this cohort, we prospectively enrolled cancer patients treated with PARPi as well as healthy volunteers in order to study the kinetics of anti-SARS-CoV-2 antibodies (NAbs) after COVID-19 vaccination. Baseline demographics, co-morbidities, and NAb levels were compared between the two groups. RESULTS: The results of the cohort of 36 patients receiving PARP inhibitors are presented here. Despite no new safety issues being noticed, their levels of SARS-CoV-2 neutralizing antibodies were significantly lower in comparison to matched healthy volunteers up to day 30 after the second dose. CONCLUSIONS: These results suggest that maintaining precautions against COVID-19 is essential for cancer patients and should be taken into consideration for the patients under treatment, while further exploration is needed to reduce the uncertainty of SARS-CoV-2 immunity among cancer patients under treatment.

SARS-CoV-2 neutralizing antibodies after first vaccination dose in breast cancer patients receiving CDK4/6 inhibitors.

Undoubtedly, the development of COVID-19 vaccines displays a critical step towards ending this devastating pandemic, considering their protective benefits in the general population. Yet, data regarding their efficacy and safety in cancer patients are limited. Herein we provide the initial analysis of immune responses after the first dose of vaccination in 21 breast cancer patients receiving cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors. The levels of neutralizing antibodies post vaccination were similar to the matched healthy controls, whereas no safety issues have been raised. Further exploration is needed to reduce the uncertainty of SARS-CoV-2 immunity among cancer patients under treatment.

Targeting post-translational histone modifying enzymes in glioblastoma.

Glioblastoma (GBM) is the most common primary brain tumor in adults, and the most lethal form of glioma, characterized by variable histopathology, aggressiveness and poor clinical outcome and prognosis. GBMs constitute a challenge for oncologists because of their molecular heterogeneity, extensive invasion, and tendency to relapse. Glioma cells demonstrate a variety of deregulated genomic pathways and extensive interplay with epigenetic alterations. Epigenetic modifications have emerged as essential players in GBM research, with biomarker potential for tumor classification and prognosis and for drug targeting. Histone posttranslational modifications (PTMs) are crucial regulators of chromatin architecture and gene expression, playing a pivotal role in malignant transformation, tumor development and progression. Alteration in the expression of genes coding for lysine and arginine methyltransferases (G9a, SUV39H1 and SETDB1) and acetyltransferases and deacetylases (KAT6A, SIRT2, SIRT7, HDAC4, 6, 9) contribute to GBM pathogenesis. In addition, proteins of the sumoylation pathway are upregulated in GBM cell lines, including E1 (SAE1), E2 (Ubc9) components, and a SUMO-specific protease (SENP1). Preclinical and clinical studies are currently in progress targeting epigenetic enzymes in gliomas, including a new generation of histone deacetylase (HDAC), protein arginine methyltransferase (PRMT) and bromodomain (BRD) inhibitors. Herein, we provide an update on recent advances in glioma epigenetic research, focusing on the role of histone modifications and the use of epigenetic therapy as a valid treatment option for glioblastoma.