Protein expression of S100A2 reveals it association with patient prognosis and immune infiltration profile in colorectal cancer.

PURPOSE: Colorectal cancer (CRC) is the third most diagnosed cancer worldwide. Despite a well-established knowledge of tumour development, biomarkers to predict patient outcomes are still required. S100 calcium-binding protein A2 (S100A2) has been purposed as a potential marker in many types of cancer, however, the prognostic value of S100A2 in CRC is rarely reported. MATERIAL AND METHODS: In this study, immunohistochemistry (IHC) was performed to identify the prognostic role of S100A2 protein expression in the tumour core of the tissue microarrays (TMAs) in colorectal cancer patients (n=787). Bulk RNA transcriptomic data was used to identify significant genes compared between low and high cytoplasmic S100A2 groups. Multiplex immunofluorescence (mIF) was performed to further study and confirm the immune infiltration in tumours with low and high cytoplasmic S100A2. RESULTS: Low cytoplasmic protein expression of S100A2 in the tumour core was associated with poor survival (HR 0.539, 95%CI 0.394-0.737, P<0.001) and other adverse tumour phenotypes. RNA transcriptomic analysis showed a gene significantly associated with the low cytoplasmic S100A2 group (AKT3, TAGLN, MYLK, FGD6 and ETFDH), which correlated with tumour development and progression. GSEA analysis identifies the enriched anti-tumour and immune activity group of genes in high cytoplasmic S100A2. Additionally, mIF staining showed that high CD3+FOXP3+ and CD163+ inversely associated with low cytoplasmic S100A2 (P<0.001, P=0.009 respectively). CONCLUSION: Our finding demonstrates a prognostic value of S100A2 together with the correlation with immune infiltration in CRC.

WNT Signalling Promotes NF-κB Activation and Drug Resistance in KRAS-Mutant Colorectal Cancer.

Approximately 40% of colorectal cancer (CRC) cases are characterized by KRAS mutations, rendering them insensitive to most CRC therapies. While the reasons for this resistance remain incompletely understood, one key aspect is genetic complexity: in CRC, oncogenic KRAS is most commonly paired with mutations that alter WNT and P53 activities ("RAP"). Here, we demonstrate that elevated WNT activity upregulates canonical (NF-κB) signalling in both Drosophila and human RAS mutant tumours. This upregulation required Toll-1 and Toll-9 and resulted in reduced efficacy of RAS pathway targeted drugs such as the MEK inhibitor trametinib. Inhibiting WNT activity pharmacologically significantly suppressed trametinib resistance in RAP tumours and more genetically complex RAP-containing 'patient avatar' models. WNT/MEK drug inhibitor combinations were further improved by targeting brm, shg, ago, rhoGAPp190 and upf1, highlighting these genes as candidate biomarkers for patients sensitive to this duel approach. These findings shed light on how genetic complexity impacts drug resistance and proposes a therapeutic strategy to reverse this resistance.

The relationship between the Glasgow Microenvironment Score and markers of epithelial-mesenchymal transition in TNM II-III colorectal cancer.

Recently published work on the Glasgow Microenvironment Score (GMS) demonstrated its relevance as a biomarker in TNM II-III colorectal cancer (CRC). Epithelial-mesenchymal transition (EMT) markers in CRC have also shown promise as prognostic biomarkers. This study aimed to assess the relationship between GMS and markers of EMT in stage II-III CRC. A previously constructed tissue microarray of CRC tumors resected between 2000 and 2007 from the Western Infirmary, Stobhill, and Gartnavel General Hospitals in Glasgow was used. Immunohistochemistry was performed for 5 markers of EMT: E-cadherin, ß-catenin, Fascin, Snail, and Zeb1. Two-hundred and thirty-eight TNM II-III CRC with valid scores for all EMT markers and GMS were assessed. The prognostic significance of markers of EMT in this cohort and relationships between GMS and markers of EMT were determined. High cytoplasmic and nuclear ß-catenin and membrane Zeb-1 were significant for worse cancer-specific survival (hazard ratio [HR] 1.67, 95% confidence interval [CI] 1.01-2.76, P < .05; HR 2.22, 95% CI 1.24-3.97, P < .01; and HR 2.00, 95% CI 1.07-3.77, P = .03, respectively). GMS 0 was associated with low membrane Fascin (P = .03), whereas membrane and cytoplasmic Fascin were observed to be highest in GMS 1, but lower in GMS 2. Nuclear ß-catenin was lowest in GMS 0, but highest in GMS 2 (P = .03), in keeping with its role in facilitating EMT. Novel associations were demonstrated between GMS categories and markers of EMT, particularly ß-catenin and Fascin, which require further investigation in independent cohorts.

Systematic review of tumour budding and association with common mutations in patients with colorectal cancer.

INTRODUCTION: Despite a well-known prognostic role in colorectal cancer, the genomic profiling of tumour budding remains to be elucidated. We aim to review the association of common mutations with tumour budding. METHODS: A systematic review of studies relating to tumour budding and genetic mutation in CRC was performed. The relationship between mutational status and tumour budding was evaluated using meta-analysis. RESULTS: A total of 6153 patients from 17 articles were included. According to the meta-analysis, high-grade tumour budding was significantly associated with KRAS mutation (OR = 1.52, 95 %CI: 1.13-2.02, P = 0.005) and MSS/pMMR (OR = 2.06, 95 %CI: 1.42-2.97, P = 0.0001). CONCLUSION: The significant association between high-grade tumour budding and mutated KRAS or MSS/pMMR may suggest a role of these mutations in the development of the tumour budding phenotype and be useful for stratifying patient outcome in CRC.

The relationship between ß-catenin and patient survival in colorectal cancer systematic review and meta-analysis.

ß-catenin is a key component of Wnt signalling, which plays a crucial role in CRC progression. Therefore, a meta-analysis was performed to assess the prognostic value of ß-catenin expression in CRC patients. PubMed and Web of Science were searched for relevant publications referring to the association between ß-catenin expression and outcome of CRC patients. Review Manager version 5.4 was employed to analysis data from 28 eligible studies (containing 5475 patients). Of these, 6 provided data on DFS, 6 provided data on CSS and 18 reports provided data on OS. High nuclear ß-catenin expression was significantly associated with poorer DFS, CSS and OS in patients with CRC whereas, low membranous ß-catenin expression was associated to poor OS. In conclusion, ß-catenin has prognostic value and potential as a biomarker to stratify patients with CRC. However, further work with high quantity tissue cohorts and patient data is required to confirm this conclusion.