2024 ASCO genitourinary cancers symposium: a focus on renal cell carcinoma.

In this article, we report the breakthrough acquisitions for renal cell carcinoma (RCC) management presented at the 2024 American Society of Clinical Oncology (ASCO) Genitourinary Cancers Symposium. The results from Keynote 564 showed an impressive overall survival (OS) advantage for pembrolizumab, in patients at higher risk of relapse after surgery and confirmed the benefit in terms of disease-free survival (DFS). Until now, pembrolizumab is the only immune checkpoint inhibitor (ICI) to prove a survival advantage. On the contrary, the results from CheckMate 914 trial showed the lack of benefit of adjuvant nivolumab. In the metastatic setting, the longer-term follow-up data of the CheckMate 9ER and CheckMate 214 trials reassessed the undoubtable role of ICI-based combination in first-line treatment, with a clear survival advantage in the subgroup of patients at intermediate/poor IMDC prognosis. No OS advantage was seen in favorable IMDC risk group patients. This 2024 ASCO Genitourinary Cancer Symposium laid the foundations for further knowledge development necessary for an increasingly personalized therapy for RCC patients.

Post nephrectomy management of localized renal cell carcinoma. From risk stratification to therapeutic evidence in an evolving clinical scenario.

Standard treatment for localized non-metastatic renal cell carcinoma (RCC) is radical or partial nephrectomy. However, after radical surgery, patients with stage II-III have a substantial risk of relapse (around 35%). To date a unique standardized classification for the risk of disease recurrence still lack. Moreover, in the last years great attention has been focused in developing systemic therapies with the aim of improving the disease-free survival (DFS) of high-risk patients, with negative results from adjuvant VEGFR-TKIs. Therefore, there is still a need for developing effective treatments for radically resected RCC patients who are at intermediate/high risk of relapse. Recently, interesting results came from immune-checkpoint inhibitors (ICIs) targeting the PD-1/PD-L1 pathway, with a significant benefit in terms of disease-free survival from adjuvant pembrolizumab. However, the conflicting results of diverse clinical trials investigating different ICI-based regimens in the adjuvant setting, together with the still immature data on the overall survival advantage of immunotherapy, requires careful considerations. Furthermore, several questions remain unanswered, primarily regarding the selection of patients who could benefit the most from immunotherapy. In this review, we have summarized the main clinical trials investigating adjuvant therapy in RCC, with a particular focus on immunotherapy. Moreover, we have analyzed the crucial issue of patients' stratification according to the risk of disease recurrence, and we have described the possible future prospective and novel agents under evaluation for perioperative and adjuvant therapies.

Targeting hypoxia-inducible factor pathways in sporadic and Von Hippel-Lindau syndrome-related kidney cancers.

Hereditary and sporadic renal cell carcinomas (RCCs) are often associated with Von Hippel-Lindau (VHL)-gene inactivation. Patients with VHL disease have an increased risk of RCC, leading to bilateral nephrectomy and dialysis. In patients with advanced RCC, no standard second-lines are available after progression to immune checkpoint inhibitors (ICIs), and new agents are required to manage progression. HIFs have emerged as a promising target for metastatic RCC patients who have progressed to ICI-based combinations, as well as for those with RCC and VHL syndrome where the goal is to delay surgery and/or and preserve kidney function and avoid dialysis. This review describes the available evidence supporting the use of the small-molecule HIF-2 alpha inhibitor, belzutifan (MK-6482), as well as other new anti-HIF molecules that have demonstrated significant efficacy in VHL disease-related RCCs as well as for sporadic RCC that has progressed after the use of ICI-based combinations.

Dietary Magnesium Alleviates Experimental Murine Colitis Through Upregulation of the Transient Receptor Potential Melastatin 6 Channel.

Background: Magnesium (Mg) is essential for human health and is absorbed mainly in the intestine. In view of the likely occurrence of an Mg deficit in inflammatory bowel disease (IBD) and the documented role of Mg in modulating inflammation, the present study addresses whether Mg availability can affect the onset and progression of intestinal inflammation. Methods: To study the correlation between Mg status and disease activity, we measured magnesemia by atomic absorption spectroscopy in a cohort of IBD patients. The effects of dietary Mg modulation were assessed in a murine model of dextran sodium sulfate (DSS)-induced colitis by monitoring magnesemia, weight, fecal occult blood, diarrhea, colon length, and histology. Expression of the transient receptor potential melastatin (TRPM) 6 channel was assessed by real-time reverse transcription polymerase chain reaction and immunohistochemistry in murine colon tissues. The effect of Mg on epithelial barrier formation/repair was evaluated in human colon cell lines. Results: Inflammatory bowel disease patients presented with a substantial Mg deficit, and serum Mg levels were inversely correlated with disease activity. In mice, an Mg-deficient diet caused hypomagnesemia and aggravated DSS-induced colitis. Colitis severely compromised intestinal Mg2+ absorption due to mucosal damage and reduction in TRPM6 expression, but Mg supplementation resulted in better restoration of mucosal integrity and channel expression. Conclusions: Our results highlight the importance of evaluating and correcting magnesemia in IBD patients. The murine model suggests that Mg supplementation may represent a safe and cost-effective strategy to reduce inflammation and restore normal mucosal function.

Magnesium Modulates Doxorubicin Activity through Drug Lysosomal Sequestration and Trafficking.

Magnesium is directly involved in the control of cell growth and survival, but its role in cancer biology and therapy is multifaceted; in particular, it is highly controversial whether magnesium levels can affect therapy outcomes. Here we investigated whether magnesium availability can modulate cellular responses to the widely used chemotherapeutic doxorubicin. We used an in vitro model consisting of mammary epithelial HC11 cells and found that high magnesium availability was correlated with diminished sensitivity both in cells chronically adapted to high magnesium concentrations and in acutely magnesium-supplemented cells. This decrease in sensitivity resulted from reduced intracellular doxorubicin accumulation in the face of a similar drug uptake rate. We observed that high-magnesium conditions caused a decrease in intracellular drug retention by altering drug lysosomal sequestration and trafficking. In our model, magnesium supplementation correspondingly modulated expression of the TRPM7 channel, which is known to control cytoskeletal organization and dynamics and may be involved in the proposed mechanism. Our findings suggest that magnesium supplementation in hypomagnesemic cancer patients may hinder response to therapy.

EGF stimulates Mg(2+) influx in mammary epithelial cells.

Magnesium is well established as a fundamental factor that regulates cell proliferation. However, the molecular mechanisms linking mitogenic signals, extracellular magnesium availability and intracellular effectors are still largely unknown. In the present study we sought to determine whether EGF regulates magnesium homeostasis in normal HC11 mammary epithelial cells. To this end, we measured Mg(2+) and Ca(2+) fluxes by confocal imaging in live cells loaded with specific fluorescent ion indicators (Mag-Fluo-4 and Fluo-4, respectively). EGF stimulation induces a rapid and sustained increase in intracellular Mg(2+), concomitantly with a rise in intracellular calcium. The increase in intracellular Mg(2+) derives from an influx from the extracellular compartment, and does not depend on Ca(2+). On the contrary, the increase in intracellular Ca(2+) derives from intracellular stores, and is impaired in the absence of extracellular magnesium. Inhibition of the EGF receptor tyrosine kinase by Tyrphostin AG1478 markedly inhibits EGF-induced Mg(2+) and Ca(2+) signals. These findings demonstrate that not only does Mg(2+) influx represent an important step in the physiological response of epithelial cells to EGF, but unexpectedly the EGF-induced Mg(2+) influx is essential for the Ca(2+) signal to occur.

From magnesium to magnesium transporters in cancer: TRPM7, a novel signature in tumour development.

Magnesium availability affects many cellular functions that are critical for tumour growth and spreading, such as proliferation, metabolism and angiogenesis. In vivo, magnesium deficiency, and the resulting inflammation, can trigger both anti- and pro-tumour effects. Recent experimental evidence indicates that altered expression of the transient receptor potential melastatin, type 7 (TRPM7) epithelial magnesium channel is a frequent finding in cancer cells and human tumour tissues, and correlates with cell proliferation and/or migration. We review the role of TRPM7 in tumour development, with particular regard to its channelling function mediating both Ca(2+) and Mg(2+) influx, as well as its kinase activity, likely regulating actomyosin contractility. The potential diagnostic and therapeutic applications based on TRPM7 detection and inhibition, are also discussed.