Hyponatremia and Cancer Progression: Possible Association with Sodium-Transporting Proteins

Sodium levels and immunotherapy efficacy in mRCC patients with bone metastases: sub analysis of Meet-Uro 15 study

Background

Immune-checkpoint inhibitors (ICIs) have significantly improved metastatic renal cell carcinoma (mRCC) prognosis, although their efficacy in patients with bone metastases (BMs) remains poorly understood. We investigated the prognostic role of natremia in pretreated RCC patients with BMs receiving immunotherapy.

Materials and methods

This retrospective multicenter study included RCC patients with BMs receiving nivolumab as second-line therapy or beyond. Inclusion criteria involved baseline sodium levels (pre-ICI) and sodium levels after 4 weeks of nivolumab initiation (post-ICI). The population was divided into two groups based on the median value, and response rates, progression-free survival (PFS), and overall survival (OS) were assessed.

Results

Among 120 eligible patients, those with pre-treatment sodium levels ≥140 mEq/L showed longer OS (18.7 vs. 12.0 months, p=0.04). Pre-treatment sodium levels ≥140 mEq/L were associated with better OS compared to levels <140 mE/L (18.7 vs. 12.0, p=0.04). Post-treatment sodium levels ≥140 mEq/L were associated with improved PFS (9.6 vs. 3.2 months) and OS (25.1 vs. 8.8 months) (p=0.05 and p<0.01, respectively). Patients with consistent sodium levels ≥140 mEq/L at both time points exhibited the best outcomes compared to those with lower values (PFS 11.5 vs. 3.3 months and OS 42.2 vs. 9.0 months, respectively, p<0.01). Disease control rate was significantly higher in the latter group (p<0.01). Multivariate analysis confirmed the prognostic significance of sodium levels.

Conclusion

Elevated sodium levels (≥140 mEq/L) pre- and post-ICI treatment correlate with better survival outcomes in mRCC patients with BMs. This finding suggests sodium level assessment as a potential prognostic factor in these patients and warrants further investigation, particularly in combination immunotherapy settings.

Prognostic role of sodium levels in colorectal cancer patients receiving aflibercept plus FOLFIRI

Aim: To investigate the impact of natremia in metastatic colorectal cancer (mCRC) patients treated with aflibercept plus folinic acid, 5-fluorouracil, oxaliplatin and irinotecan (FOLFIRI). Patients & methods: A total of 84 mCRC patients receiving aflibercept plus FOLFIRI as second-line treatment were enrolled and divided into two groups based on their median sodium value. Progression-free survival and overall survival were analyzed. Results: Patients with sodium levels ≥140 mEq/l had significantly longer median progression-free survival (4.1 vs 2 months; p < 0.01) and median overall survival (12 vs 7.3 months; p < 0.01) compared with those with lower levels. Conclusion: This study suggests that higher pretreatment serum sodium levels are associated with improved outcomes in mCRC patients receiving aflibercept and FOLFIRI, potentially serving as a prognostic marker to aid treatment management.

Voltage-Gated Sodium Channel NaV1.7 Inhibitors with Potent Anticancer Activities in Medullary Thyroid Cancer Cells

Our results from quantitative RT-PCR, Western blotting, immunohistochemistry, and the tissue microarray of medullary thyroid cancer (MTC) cell lines and patient specimens confirm that VGSC subtype NaV1.7 is uniquely expressed in aggressive MTC and not expressed in normal thyroid cells and tissues. We establish the druggability of NaV1.7 in MTC by identifying a novel inhibitor (SV188) and investigate its mode of binding and ability to inhibit INa current in NaV1.7. The whole-cell patch-clamp studies of the SV188 in the NaV1.7 channels expressed in HEK-293 cells show that SV188 inhibited the INa current in NaV1.7 with an IC50 value of 3.6 µM by a voltage- and use-dependent blockade mechanism, and the maximum inhibitory effect is observed when the channel is open. SV188 inhibited the viability of MTC cell lines, MZ-CRC-1 and TT, with IC50 values of 8.47 μM and 9.32 μM, respectively, and significantly inhibited the invasion of MZ-CRC-1 cells by 35% and 52% at 3 μM and 6 μM, respectively. In contrast, SV188 had no effect on the invasion of TT cells derived from primary tumor, which have lower basal expression of NaV1.7. In addition, SV188 at 3 μM significantly inhibited the migration of MZ-CRC-1 and TT cells by 27% and 57%, respectively.

NALCN is a potential biomarker and therapeutic target in human cancers

Background: Sodium leak channel non-selective (NALCN), known as a voltage-independent Na⁺ channel, is increasingly considered to play vital roles in tumorigenesis and metastasis of human cancers. However, no comprehensive pan-cancer analysis of NALCN has been conducted. Our study aims to explore the potential diagnostic, prognostic and therapeutic value of NALCN in human cancers. Methods: Through comprehensive application of datasets from Human Protein Atlas (HPA), The Cancer Genome Atlas (TCGA), Cancer Cell Line Encyclopedia (CCLE), Enhanced Version of Tumor Immune Estimation Resource (TIMER2.0), Tumor and Immune System Interaction Database (TISIDB), The University of Alabama at Birmingham Cancer data analysis Portal (UALCAN), cBioPortal, GeneMANIA and Search Tool for the Retrieval of Interaction Gene/Proteins (STRING) databases, we explored the potential roles of NALCN in different cancers. The differential expression, prognostic implications, pathological stages and grades, molecular and immune subtypes, diagnostic accuracy, tumor mutation burden (TMB), microsatellite instability (MSI), mismatch repair (MMR) genes, immune checkpoint genes, chemokine genes, major histocompatibility complex (MHC)-related genes, tumor-infiltrating immune cells (TIICs), promoter methylation, mutations, copy number alteration (CNA), and functional enrichment related to NALCN were analyzed. Results: Most cancers lowly expressed NALCN. Upregulated NALCN expression was associated with poor or better prognosis in different cancers. Moreover, NALCN was correlated with clinicopathological features in multiple cancers. NALCN showed high diagnostic accuracy in 5 caner types. NALCN is highly linked with immune-related biomarkers, immune-related genes and TIICs. Significant methylation changes and genetic alteration of NALCN can be observed in many cancers. Enrichment analysis showed that NALCN is closely related to multiple tumor-related signaling pathways. Conclusion: Our study revealed the vital involvement of NALCN in cancer. NALCN can be used as a prognostic biomarker for immune infiltration and clinical outcomes, and has potential diagnostic and therapeutic implications.

Water transport regulates nucleus volume, cell density, Young's modulus, and E-cadherin expression in tumor spheroids

Cell volume is maintained by the balance of water and solutes across the cell membrane and plays an important role in mechanics and biochemical signaling in cells. Here, we assess the relationship between cell volume, mechanical properties, and E-cadherin expression in three-dimensional cultures for ovarian cancer. To determine the effect of water transport in multi-cellular tumors, ovarian cancer spheroids were subjected to hypotonic and hypertonic shock using water and sucrose mixtures, respectively. Increased osmolality resulted in decreased nucleus volume, increased Young's modulus, and increased tumor cell density in ovarian cancer spheroids. Next, we looked at the reversibility of mechanics and morphology after 5 min of osmotic shock and found that spheroids had a robust ability to return to their original state. Finally, we quantified the size of E-cadherin clusters at cell-cell junctions and observed a significant increase in aggregate size following 30 min of hypertonic and hypotonic osmotic shocks. Yet, these effects were not apparent after 5 min of osmotic shock, illustrating a temporal difference between E-cadherin regulation and the immediate mechanical and morphology changes. Still, the osmotically induced E-cadherin aggregates which formed at the 30-minute timepoint was reversible when spheroids were replenished with isotonic medium. Altogether, this work demonstrated an important role of osmolality in transforming mechanical, morphology, and molecular states.

Tumor-derived endomucin promotes colorectal cancer proliferation and metastasis

BACKGROUND

Endomucin (EMCN) is a type I transmembrane glycoprotein and a mucin-like component of the endothelial cell glycocalyx. The mechanism of EMCN action in colorectal cancer (CRC) remains unclear.

AIMS

Our aim was to explore the role of EMCN in the progression of CRC.

MATERIALS & METHODS

We examined EMCN expression in CRC tissues and normal para-carcinoma tissues. The function and mechanisms of EMCN were checked in CRC cell lines and in mouse xenograft. Additionally, we used co-immunoprecipitation and mass spectrometry to identify the potential EMCN-binding proteins. Functional annotation analysis showed where these genes were enriched.

RESULTS

We found that EMCN was overexpressed in tumor tissues compared with that in normal para-carcinoma tissues. We also found that overexpression of EMCN induced CRC proliferation and metastasis both in vitro and in vivo. EMCN knockdown prevents epithelial-mesenchymal transition in vitro. We identified 178 potential EMCN-binding partners. Furthermore, functional annotation analysis indicated that these genes were considerably enriched in carcinogenic-related functions and pathways. Collectively, the identification of EMCN-binding partners enhanced our understanding of the mechanism of EMCN-mediated malignant phenotypes, and this research may provide valuable insights into the molecular mechanisms underlying CRC.

CONCLUSION

Tumor-derived endomucin promotes colorectal cancer proliferation and metastasis. We identified 178 EMCN-binding proteins and initially screened three potential EMCN-interacting proteins: NALCN, and TPM2, ANKK1. Our study provides valuable insights into the molecular mechanisms underlying CRC development.