NFκB signalling in colorectal cancer: Examining the central dogma of IKKα and IKKß signalling.

The NFκB pathway, known as the central regulator of inflammation, has a well-established role in colorectal cancer (CRC) initiation, progression, and therapy resistance. Due to the pathway's overarching roles in CRC, there have been efforts to characterise NFκB family members and target the pathway for therapeutic intervention. Initial research illustrated that the canonical NFκB pathway, driven by central kinase IKKß, was a promising target for drug intervention. However, dose limiting toxicities and specificity concerns have resulted in failure of IKKß inhibitors in clinical trials. The field has turned to look at targeting the less dominant kinase, IKKα, which along with NFκB inducing kinase (NIK), drives the lesser researched non-canonical NFκB pathway. However prognostic studies of the non-canonical pathway have produced conflicting results. There is emerging evidence that IKKα is involved in other signalling pathways, which lie outside of canonical and non-canonical NFκB signalling. Evidence suggests that some of these alternative pathways involve a truncated form of IKKα, and this may drive poor cancer-specific survival in CRC. This review aims to explore the multiple components of NFκB signalling, highlighting that NIK may be the central kinase for non-canonical NFκB signalling, and that IKKα is involved in novel pathways which promote CRC.

14-3-3σ/Stratifin and p21 limit AKT-related malignant progression in skin carcinogenesis following MDM2-associated p53 loss.

To study mechanisms driving/inhibiting skin carcinogenesis, stage-specific expression of 14-3-3σ (Stratifin) was analyzed in skin carcinogenesis driven by activated rasHa/fos expression (HK1.ras/fos) and ablation of PTEN-mediated AKT regulation (K14.creP/Δ5PTENflx/flx). Consistent with 14-3-3σ roles in epidermal differentiation, HK1.ras hyperplasia and papillomas displayed elevated 14-3-3σ expression in supra-basal keratinocytes, paralleled by supra-basal p-MDM2166 activation and sporadic p-AKT473 expression. In bi-genic HK1.fos/Δ5PTENflx/flx hyperplasia, basal-layer 14-3-3σ expression appeared, and alongside p53/p21, was associated with keratinocyte differentiation and keratoacanthoma etiology. Tri-genic HK1.ras/fos-Δ5PTENflx/flx hyperplasia/papillomas initially displayed increased basal-layer 14-3-3σ, suggesting attempts to maintain supra-basal p-MDM2166 and protect basal-layer p53. However, HK1.ras/fos-Δ5PTENflx/flx papillomas exhibited increasing basal-layer p-MDM2166 activation that reduced p53, which coincided with malignant conversion. Despite p53 loss, 14-3-3σ expression persisted in well-differentiated squamous cell carcinomas (wdSCCs) and alongside elevated p21, limited malignant progression via inhibiting p-AKT1473 expression; until 14-3-3σ/p21 loss facilitated progression to aggressive SCC exhibiting uniform p-AKT1473. Analysis of TPA-promoted HK1.ras-Δ5PTENflx/flx mouse skin, demonstrated early loss of 14-3-3σ/p53/p21 in hyperplasia and papillomas, with increased p-MDM2166/p-AKT1473 that resulted in rapid malignant conversion and progression to poorly differentiated SCC. In 2D/3D cultures, membranous 14-3-3σ expression observed in normal HaCaT and SP1ras61 papilloma keratinocytes was unexpectedly detected in malignant T52ras61/v-fos SCC cells cultured in monolayers, but not invasive 3D-cells. Collectively, these data suggest 14-3-3σ/Stratifin exerts suppressive roles in papillomatogenesis via MDM2/p53-dependent mechanisms; while persistent p53-independent expression in early wdSCC may involve p21-mediated AKT1 inhibition to limit malignant progression.

The combined tumour-based Fascin/Snail and stromal periostin reveals the effective prognosis prediction in colorectal cancer patients.

Colorectal cancer (CRC) is the third most common malignancy cause of cancer-related mortality worldwide. Epithelial-mesenchymal transition (EMT) promotes cancer metastasis and a tumour-based Glasgow EMT score was associated with adverse clinical features and poor prognosis. In this study, the impact of using the established five tumour-based EMT markers consisting of E-cadherin (E-cad), ß-catenin (ß-cat), Snail, Zeb-1, and Fascin in combination with the stromal periostin (PN) on the prediction of CRC patients' prognosis were invesigated. Formalin-fixed paraffin-embedded tissues of 202 CRC patients were studies the expressions of E-cad, ß-cat, Snail, Zeb-1, Fascin, and PN by immunohistochemistry. Individually, cytoplasmic Fascin (Fc), cytoplasmic Snail (Sc), nuclear Snail (Sn), stromal Snail (Ss), and stromal PN (Ps) were significantly associated with reduced survival. A combination of Ps with Fc, Fs, and Sn was observed in 2 patterns including combined Fc, Fs, and Ps (FcFsPs) and Fc, Sn, and Ps (FcSnPs). These combinations enhanced the prognostic power compared to individual EMT markers and were independent prognostic markers. As the previously established scoring method required five markers and stringent criteria, its clinical use might be limited. Therefore, using these novel combined prognostic markers, either FcFsPs or FcSnPs, may be useful in predicting CRC patient outcomes.

JAK/STAT3 represents a therapeutic target for colorectal cancer patients with stromal-rich tumors.

Colorectal cancer (CRC) is a heterogenous malignancy underpinned by dysregulation of cellular signaling pathways. Previous literature has implicated aberrant JAK/STAT3 signal transduction in the development and progression of solid tumors. In this study we investigate the effectiveness of inhibiting JAK/STAT3 in diverse CRC models, establish in which contexts high pathway expression is prognostic and perform in depth analysis underlying phenotypes. In this study we investigated the use of JAK inhibitors for anti-cancer activity in CRC cell lines, mouse model organoids and patient-derived organoids. Immunohistochemical staining of the TransSCOT clinical trial cohort, and 2 independent large retrospective CRC patient cohorts was performed to assess the prognostic value of JAK/STAT3 expression. We performed mutational profiling, bulk RNASeq and NanoString GeoMx® spatial transcriptomics to unravel the underlying biology of aberrant signaling. Inhibition of signal transduction with JAK1/2 but not JAK2/3 inhibitors reduced cell viability in CRC cell lines, mouse, and patient derived organoids (PDOs). In PDOs, reduced Ki67 expression was observed post-treatment. A highly significant association between high JAK/STAT3 expression within tumor cells and reduced cancer-specific survival in patients with high stromal invasion (TSPhigh) was identified across 3 independent CRC patient cohorts, including the TrasnSCOT clinical trial cohort. Patients with high phosphorylated STAT3 (pSTAT3) within the TSPhigh group had higher influx of CD66b + cells and higher tumoral expression of PDL1. Bulk RNAseq of full section tumors showed enrichment of NFκB signaling and hypoxia in these cases. Spatial deconvolution through GeoMx® demonstrated higher expression of checkpoint and hypoxia-associated genes in the tumor (pan-cytokeratin positive) regions, and reduced lymphocyte receptor signaling in the TME (pan-cytokeratin- and αSMA-) and αSMA (pan-cytokeratin- and αSMA +) areas. Non-classical fibroblast signatures were detected across αSMA + regions in cases with high pSTAT3. Therefore, in this study we have shown that inhibition of JAK/STAT3 represents a promising therapeutic strategy for patients with stromal-rich CRC tumors. High expression of JAK/STAT3 proteins within both tumor and stromal cells predicts poor outcomes in CRC, and aberrant signaling is associated with distinct spatially-dependant differential gene expression.

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.

Spatially Resolved Transcriptomics Deconvolutes Prognostic Histological Subgroups in Patients with Colorectal Cancer and Synchronous Liver Metastases.

Strong immune responses in primary colorectal cancer correspond with better patient survival following surgery compared with tumors with predominantly stromal microenvironments. However, biomarkers to identify patients with colorectal cancer liver metastases (CRLM) with good prognosis following surgery for oligometastatic disease remain elusive. The aim of this study was to determine the practical application of a simple histological assessment of immune cell infiltration and stromal content in predicting outcome following synchronous resection of primary colorectal cancer and CRLM and to interrogate the underlying functional biology that drives disease progression. Samples from patients undergoing synchronous resection of primary colorectal cancer and CRLM were evaluated in detail through histological assessment, panel genomic and bulk transcriptomic assessment, IHC, and GeoMx spatial transcriptomics (ST) analysis. High immune infiltration of metastases was associated with improved cancer-specific survival. Bulk transcriptomic analysis was confounded by stromal content, but ST demonstrated that the invasive edge of the metastases of long-term survivors was characterized by adaptive immune cell populations enriched for type II IFN signaling and MHC-class II antigen presentation. In contrast, patients with poor prognosis demonstrated increased abundance of regulatory T cells and neutrophils with enrichment of Notch and TGFß signaling pathways at the metastatic tumor center. In summary, histological assessment can stratify outcomes in patients undergoing synchronous resection of CRLM, suggesting that it has potential as a prognostic biomarker. Furthermore, ST analysis has revealed significant intratumoral and interlesional heterogeneity and identified the underlying transcriptomic programs driving each phenotype. SIGNIFICANCE: Spatial transcriptomics uncovers heterogeneity between patients, between matched lesions in the same patient, and within individual lesions and identifies drivers of metastatic progression in colorectal cancer with reactive and suppressed immune microenvironments.

Carbonic anhydrase IX-related tumoral hypoxia predicts worse prognosis in breast cancer: A systematic review and meta-analysis.

Background: Tumoral hypoxia is associated with aggressiveness in many cancers including breast cancer. However, measuring hypoxia is complicated. Carbonic anhydrase IX (CAIX) is a reliable endogenous marker of hypoxia under the control of the master regulator hypoxia-inducible factor-1α (HIF-1α). The expression of CAIX is associated with poor prognosis in many solid malignancies; however, its role in breast cancer remains controversial. Methods: The present study performed a meta-analysis to evaluate the correlation between CAIX expression and disease-free survival (DFS) and overall survival (OS) in breast cancer. Results: A total of 2,120 publications from EMBASE, PubMed, Cochrane, and Scopus were screened. Of these 2,120 publications, 272 full texts were reviewed, and 27 articles were included in the meta-analysis. High CAIX was significantly associated with poor DFS (HR = 1.70, 95% CI = 1.39-2.07, p < 0.00001) and OS (HR = 2.02, 95% CI 1.40-2.91, p = 0.0002) in patients with breast cancer. When stratified by subtype, the high CAIX group was clearly associated with shorter DFS (HR = 2.09, 95% CI =1.11-3.92, p = 0.02) and OS (HR = 2.50, 95% CI =1.53-4.07, p = 0.0002) in TNBC and shorter DFS in ER+ breast cancer (HR = 1.81 95% CI =1.38-2.36, p < 0.0001). Conclusion: High CAIX expression is a negative prognostic marker of breast cancer regardless of the subtypes.

Dual inhibition of HSF1 and DYRK2 impedes cancer progression.

Preserving proteostasis is a major survival mechanism for cancer. Dual specificity tyrosine phosphorylation-regulated kinase 2 (DYRK2) is a key oncogenic kinase that directly activates the transcription factor heat-shock factor 1 (HSF1) and the 26S proteasome. Targeting DYRK2 has proven to be a tractable strategy to target cancers sensitive to proteotoxic stress; however, the development of HSF1 inhibitors remains in its infancy. Importantly, multiple other kinases have been shown to redundantly activate HSF1 that promoted ideas to directly target HSF1. The eventual development of direct HSF1 inhibitor KRIBB11 suggests that the transcription factor is indeed a druggable target. The current study establishes that concurrent targeting of HSF1 and DYRK2 can indeed impede cancer by inducing apoptosis faster than individual targetting. Furthermore, targeting the DYRK2-HSF1 axis induces death in proteasome inhibitor-resistant cells and reduces triple-negative breast cancer (TNBC) burden in ectopic and orthotopic xenograft models. Together the data indicate that cotargeting of kinase DYRK2 and its substrate HSF1 could prove to be a beneficial strategy in perturbing neoplastic malignancies.

CXCL8 expression is associated with advanced stage, right sidedness, and distinct histological features of colorectal cancer.

CXCL8 is an inflammatory chemokine elevated in the colorectal cancer (CRC) tumour microenvironment. CXCR2, the major receptor for CXCL8, is predominantly expressed by neutrophils. In the cancer setting, CXCL8 plays important roles in neutrophil chemotaxis, facilitating angiogenesis, invasion, and metastasis. This study aimed to assess the spatial distribution of CXCL8 mRNA expression in CRC specimens, explore associations with clinical characteristics, and investigate the underlying biology of aberrant CXCL8 levels. CXCR2 expression was also assessed in a second cohort of unique CRC primary tumours and synchronously resected matched liver metastases. A previously constructed tissue microarray consisting of a cohort of stage I-IV CRC patients undergoing surgical resection with curative intent (n = 438) was probed for CXCL8 via RNAscope®. Analysis was performed using HALO® digital pathology software to quantify expression in the tumour and stromal compartments. Scores were assessed for association with clinical characteristics. Mutational analyses were performed on a subset of these patients to determine genomic differences in patients with high CXCL8 expression. A second cohort of stage IV CRC patients with primary and matched metastatic liver tumours was stained via immunohistochemistry for CXCR2, and scores were assessed for clinical significance. CXCL8 expression within the stromal compartment was associated with reduced cancer-specific survival in the first cohort (p = 0.035), and this relationship was potentiated in right-sided colon cancer cases (p = 0.009). High CXCL8 within the stroma was associated with driving a more stromal-rich phenotype and the presence of metastases. When stromal CXCL8 scores were combined with tumour-infiltrating macrophage counts or systemic neutrophil counts, patients classified as high for both markers had significantly poorer prognosis. CXCR2+ immune cell infiltration was associated with increased stromal invasion in liver metastases (p = 0.037). These data indicate a role for CXCL8 in driving unfavourable tumour histological features and promoting metastases. This study suggests that inhibiting CXCL8/CXCR2 should be investigated in patients with right-sided colonic disease and stroma-rich tumours.

The Relationship Between the Tumor Cell Expression of Hypoxic Markers and Survival in Patients With ER-positive Invasive Ductal Breast Cancer.

The prognostic significance of hypoxia markers, hypoxia-inducible factor-1α (HIF-1α), hypoxia-inducible factor-2α (HIF-2α), and carbonic anhydrase IX (CAIX), was investigated in estrogen receptor (ER)-positive breast cancer patients. Immunohistochemistry determined the expression of makers in two independent ductal ER-positive cohorts (Training set, n=373 and Validation set, n=285) and was related to clinicopathological parameters and disease-free survival (DFS). In the training cohort, nuclear HIF-1α (1) was independently associated with poorer DFS in luminal A tumors [hazard ratio (HR) = 0.53 95% confidence interval (CI): 0.30-0.94, p=0.030]. In the validation cohort, both HIF-1α (1) and CAIX were independently associated with decreased DFS in the entire cohort (HR = 1.85 95% CI: 1.10-3.11, p=0.019; HR = 1.74 95% CI: 1.08-2.82, p=0.023), in luminal A disease (HR = 1.98 95% CI: 1.02-3.83, p=0.042), and in luminal B disease (HR = 2.75 95% CI: 1.66-4.55, p<0.001), respectively. Taken together, elevated cytoplasmic HIF-1α (1) expression was an independent prognostic factor in luminal A disease, whereas CAIX was an independent prognostic factor in luminal B disease. Further work in large tissue cohorts is required.

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.

Molecular mechanisms of tumour budding and its association with microenvironment in colorectal cancer.

Colorectal cancer (CRC) is the third most common cancer worldwide. Poor survival of CRC associated with the development of tumour metastasis led to the investigation of the potential biomarkers to predict outcomes in CRC patients. Tumour budding (TB) is a well-known independent prognostic marker for poor survival and disease metastasis. Therefore, it has been suggested that TB status is included in routine clinicopathological factors for risk assessment in CRC. In contrast with a vast majority of studies regarding the prognostic power of TB, there is no clear evidence pertaining to the underlying molecular mechanism driving this phenotype, or an understanding of TB relationship with the tumour microenvironment (TME). The aim of the present study is to present a comprehensive review of TB and tumour cell signalling pathways together with the cross-talk of immune cells that could drive TB formation in CRC.

Spatial expression of IKK-alpha is associated with a differential mutational landscape and survival in primary colorectal cancer.

BACKGROUND: To understand the relationship between key non-canonical NF-κB kinase IKK-alpha(α), tumour mutational profile and survival in primary colorectal cancer. METHODS: Immunohistochemical expression of IKKα was assessed in a cohort of 1030 patients who had undergone surgery for colorectal cancer using immunohistochemistry. Mutational tumour profile was examined using a customised gene panel. Immunofluorescence was used to identify the cellular location of punctate IKKα expression. RESULTS: Two patterns of IKKα expression were observed; firstly, in the tumour cell cytoplasm and secondly as discrete 'punctate' areas in a juxtanuclear position. Although cytoplasmic expression of IKKα was not associated with survival, high 'punctate' IKKα expression was associated with significantly reduced cancer-specific survival on multivariate analysis. High punctate expression of IKKα was associated with mutations in KRAS and PDGFRA. Dual immunofluorescence suggested punctate IKKα expression was co-located with the Golgi apparatus. CONCLUSIONS: These results suggest the spatial expression of IKKα is a potential biomarker in colorectal cancer. This is associated with a differential mutational profile highlighting possible distinct signalling roles for IKKα in the context of colorectal cancer as well as potential implications for future treatment strategies using IKKα inhibitors.

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.

Relationship between immune checkpoint proteins, tumour microenvironment characteristics, and prognosis in primary operable colorectal cancer.

The tumour microenvironment is an important factor for colorectal cancer prognosis, affecting the patient's immune response. Immune checkpoints, which regulate the immune functions of lymphocytes, may provide prognostic power. This study aimed to investigate the prognostic value of the immune checkpoints TIM-3, LAG-3 and PD-1 in patients with stage I-III colorectal cancer. Immunohistochemistry was employed to detect TIM-3, LAG-3, PD-1 and PD-L1 in 773 patients with stage I-III colorectal cancer. Immune checkpoint protein expression was assessed in tumour cells using the weighted histoscore, and in immune cells within the stroma using point counting. Scores were analysed for associations with survival and clinical factors. High tumoural LAG-3 (hazard ratio [HR] 1.45 95% confidence interval [CI] 1.00-2.09, p = 0.049) and PD-1 (HR 1.34 95% CI 1.00-1.78, p = 0.047) associated with poor survival, whereas high TIM-3 (HR 0.60 95% CI 0.42-0.84, p = 0.003), LAG-3 (HR 0.58 95% CI 0.40-0.87, p = 0.006) and PD-1 (HR 0.65 95% CI 0.49-0.86, p = 0.002) on immune cells within the stroma associated with improved survival, while PD-L1 in the tumour (p = 0.487) or the immune cells within the stroma (p = 0.298) was not associated with survival. Furthermore, immune cell LAG-3 was independently associated with survival (p = 0.017). Checkpoint expression scores on stromal immune cells were combined into a Combined Immune Checkpoint Stromal Score (CICSS), where CICSS 3 denoted all high, CICSS 2 denoted any two high, and CICSS 1 denoted other combinations. CICSS 3 was associated with improved patient survival (HR 0.57 95% CI 0.42-0.78, p = 0.001). The results suggest that individual and combined high expression of TIM-3, LAG-3, and PD-1 on stromal immune cells are associated with better colorectal cancer prognosis, suggesting there is added value to investigating multiple immune checkpoints simultaneously.

The stress-responsive kinase DYRK2 activates heat shock factor 1 promoting resistance to proteotoxic stress.

To survive proteotoxic stress, cancer cells activate the proteotoxic-stress response pathway, which is controlled by the transcription factor heat shock factor 1 (HSF1). This pathway supports cancer initiation, cancer progression and chemoresistance and thus is an attractive therapeutic target. As developing inhibitors against transcriptional regulators, such as HSF1 is challenging, the identification and targeting of upstream regulators of HSF1 present a tractable alternative strategy. Here we demonstrate that in triple-negative breast cancer (TNBC) cells, the dual specificity tyrosine-regulated kinase 2 (DYRK2) phosphorylates HSF1, promoting its nuclear stability and transcriptional activity. DYRK2 depletion reduces HSF1 activity and sensitises TNBC cells to proteotoxic stress. Importantly, in tumours from TNBC patients, DYRK2 levels positively correlate with active HSF1 and associates with poor prognosis, suggesting that DYRK2 could be promoting TNBC. These findings identify DYRK2 as a key modulator of the HSF1 transcriptional programme and a potential therapeutic target.

High NRF2 Levels Correlate with Poor Prognosis in Colorectal Cancer Patients and with Sensitivity to the Kinase Inhibitor AT9283 In Vitro.

Aberrant hyperactivation of nuclear factor erythroid 2 (NF-E2) p45-related factor 2 (NRF2) is a common event in many tumour types and associates with resistance to therapy and poor patient prognosis; however, its relevance in colorectal tumours is not well-established. Measuring the expression of surrogate genes for NRF2 activity in silico, in combination with validation in patients' samples, we show that the NRF2 pathway is upregulated in colorectal tumours and that high levels of nuclear NRF2 correlate with a poor patient prognosis. These results highlight the need to overcome the protection provided by NRF2 and present an opportunity to selectively kill cancer cells with hyperactive NRF2. Exploiting the CRISPR/Cas9 technology, we generated colorectal cancer cell lines with hyperactive NRF2 and used them to perform a drug screen. We identified AT9283, an Aurora kinase inhibitor, for its selectivity towards killing cancer cells with hyperactive NRF2 as a consequence to either genetic or pharmacological activation. Our results show that hyperactivation of NRF2 in colorectal cancer cells might present a vulnerability that could potentially be therapeutically exploited by using the Aurora kinase inhibitor AT9283.

The relationship between members of the canonical NF-kB pathway, tumour microenvironment and cancer specific survival in colorectal cancer patients.

BACKGROUND: The aim of this study was to investigate the role of the upstream kinase TAK1 and the canonical NF-κB pathway colorectal in cancer (CRC). Immunohistochemistry was used to assess the expression of TAK1/pTAK1 and canonical NF-κB pathway members in a tissue microarray of 242 patients. The relationship between expression, the tumour microenvironment and cancer-specific survival were examined. RESULTS: All the investigated members of the pathway were expressed in CRC tissue. In addition, cytoplasmic pTAK1 was associated with the tumour microenvironment (P=0.045) and cancer-specific survival (CSS) (P=0.032). When cytoplasmic pTAK1 was stratified by BRAF status, cytoplasmic pTAK1 expression association with CSS was strengthened (P=0.014). Cytoplasmic IKKß was significantly associated with the inflammatory cell infiltrate (P=0.015) as graded by Klintrup Makinen grade, systemic inflammation as assessed by neutrophil-lymphocyte ratio (P=0.03) and CSS (P=0.046). On multivariate analysis cytoplasmic IKKß was independently associated with CSS (HR 1.75,95%CI 1.05-2.91, P=0.033). CONCLUSION: Cytoplasmic pTAK1 was significantly associated with CSS and this was enhanced in patients with tumours that expressed wild type BRAF. High expression of cytoplasmic IKKß was significantly associated with decreased CSS and with markers of the tumour microenvironment. These results support the hypothesis that NF-κB pathway members are poor prognostic markers in patients with CRC, but this requires to be validated in a large independent cohort.

The association between markers of tumour cell metabolism, the tumour microenvironment and outcomes in patients with colorectal cancer.

Tumour cell anaerobic metabolism has been reported to be a prognostic factor in colorectal cancer. The present study investigated the association between monocarboxylate transporter (MCT) 1, MCT 2, lactate dehydrogenase (LDH) 1 and LDH 5, the tumour microenvironment, and outcome in patients with colorectal cancer. A cohort of 150 patients with stage I-III CRC were utilised to assess tumour cell expression of MCT-1, MCT-2, LDH-1 and LDH-5 by immunohistochemistry. Expression levels were dichotomised and associations with tumour factors, the tumour microenvironment and survival analysed. Nuclear LDH-5 associates with poor prognosis (HR 1.68 95% CI 0.99-2.84, p = 0.050) and trends toward increased tumour stroma percentage (TSP, p = 0.125). Cytoplasmic MCT-2 also trends toward increased TSP (p = 0.081). When combined into a single score; nuclear LDH-5 + TSP significantly associated with decreased survival independent of stage (HR 2.61 95% CI 1.27-5.35, p = 0.009), increased tumour budding (p = 0.002) and decreased stromal T-lymphocytes (p = 0.014). Similarly, cytoplasmic MCT-2 + TSP significantly associated with decreased survival (HR 2.32 95% CI 1.31-4.11, p = 0.003), decreased necrosis (p = 0.039), and increased tumour budding (p = 0.004). The present study reports that the combination of TSP and nuclear LDH-5 was significantly associated with survival, increased tumour budding, and decreased stromal T-lymphocytes. This supports the hypothesis that increased stromal invasion promotes tumour progression via modulation of tumour metabolism. Moreover, MCT-2 and LDH-5 may provide promising therapeutic targets for patients with stromal-rich CRC.