Both STAT1 and STAT3 are favourable prognostic determinants in colorectal carcinoma

Anti-cancer potential of casein and its derivatives: novel strategies for cancer treatment

Cancer is one of the leading causes of death worldwide, with over 10 million fatalities annually. While tumors can be surgically removed and treated with chemotherapy, radiotherapy, immunotherapy, hormonal therapy, or combined therapies, current treatments often result in toxic side effects in normal tissue. Therefore, researchers are actively seeking ways to selectively eliminate cancerous cells, minimizing the toxic side effects in normal tissue. Caseins and its derivatives have shown promising anti-cancer potential, demonstrating antitumor and cytotoxic effects on cells from various tumor types without causing harm to normal cells. Collectively, these data reveals advancements in the study of caseins and their derivative peptides, particularly providing a comprehensive understanding of the molecular mechanism of action in cancer therapy. These mechanisms occur through various signaling pathways, including (i) the increase of interferon-associated STAT1 signaling, (ii) the suppression of stemness-related markers such as CD44, (iii) the attenuation of the STAT3/HIF1-α signaling, (iv) the down-expression of uPAR and PAI-1, (v) the loss of mitochondrial membrane potential and reduced intracellular ATP production, (vi) the increase of caspase-3 activity, and (vii) the suppression of TLR4/NF-кB signaling. Therefore, we conclude that casein could be an effective adjuvant for cancer treatment.

PABPC1L Induces IDO1 to Promote Tryptophan Metabolism and Immune Suppression in Renal Cell Carcinoma

The tumor microenvironment (TME) in renal cell carcinomas (RCC) is marked by substantial immunosuppression and immune resistance despite having extensive T-cell infiltration. Elucidation of the mechanisms underlying immune evasion could help identify therapeutic strategies to boost the efficacy of immune checkpoint blockade (ICB) in RCC. This study uncovered a mechanism wherein the polyadenylate-binding protein PABPC1L modulates indoleamine 2,3-dioxygenase 1 (IDO1), a prospective target for immunotherapy. PABPC1L was markedly upregulated in RCC, and high PABPC1L expression correlated with unfavorable prognosis and resistance to ICB. PABPC1L bolstered tryptophan metabolism by upregulating IDO1, inducing T-cell dysfunction and Treg infiltration. PABPC1L enhanced the stability of JAK2 mRNA, leading to increased JAK2-STAT1 signaling that induced IDO1 expression. Additionally, PABPC1L-induced activation of the JAK2-STAT1 axis created a positive feedback loop to promote PABPC1L transcription. Conversely, loss of PABPC1L diminished IDO1 expression, mitigated cytotoxic T-cell suppression, and enhanced responsiveness to anti-PD-1 therapy in patient-derived xenograft models. These findings reveal the crucial role of PABPC1L in facilitating immune evasion in RCC and indicate that inhibiting PABPC1L could be a potential immunotherapeutic approach in combination with ICB to improve patient outcomes.

SIGNIFICANCE

PABPC1L functions as a key factor in renal cell carcinoma immune evasion, enhancing IDO1 and impeding T-cell function, and represents a potential target to enhance the efficacy of immune checkpoint blockade therapy.

Inhibition of SIRT7 promotes STAT1 activation and STAT1-dependent signaling in hepatocellular carcinoma

The signal transducer and activator of transcription 1 (STAT1) plays a crucial role in regulating tumor progression. However, the mechanisms governing its phosphorylation and biological functions remain incompletely understood. Here, we present compelling evidence indicating that knockdown of SIRT7 inhibits Smurf1-induced ubiquitination of STAT1, consequently impeding the proteasome pathway degradation of STAT1. This inhibition leads to increased stability of STAT1 and enhanced binding to JAK1. Importantly, SIRT7 exerts a negative regulatory effect on STAT1 activation and IFN-γ/STAT1 signaling in hepatocellular carcinoma (HCC). Etoposide treatment not only facilitates STAT1 activation but also downregulates SIRT7 expression. Notably, knockdown of STAT1 in SIRT7-deficient cells attenuates the increase in cell apoptosis induced by Etoposide treatment. In conclusion, our data shed light on the intricate interplay between ubiquitination, STAT1, SIRT7, and Smurf1, elucidating their impact on STAT1-related signaling. These insights contribute to a more comprehensive understanding of the molecular mechanisms involved in STAT1 regulation and suggest potential avenues for the development of targeted therapies against cancer.

Monogenic deficiency in murine intestinal Cdc42 leads to mucosal inflammation that induces crypt dysplasia

CDC42 controls intestinal epithelial (IEC) stem cell (IESC) division. How aberrant CDC42 initiates intestinal inflammation or neoplasia is unclear. We utilized models of inflammatory bowel diseases (IBD), colorectal cancer, aging, and IESC injury to determine the loss of intestinal Cdc42 upon inflammation and neoplasia. Intestinal specimens were collected to determine the levels of CDC42 in IBD or colorectal cancer. Cdc42 floxed mice were crossed with Villin-Cre, Villin-CreERT2 and/or Lgr5-eGFP-IRES-CreERT2, or Bmi1-CreERT2 mice to generate Cdc42 deficient mice. Irradiation, colitis, aging, and intestinal organoid were used to evaluate CDC42 upon mucosal inflammation, IESC/progenitor regenerative capacity, and IEC repair. Our studies revealed that increased CDC42 in colorectal cancer correlated with lower survival; in contrast, lower levels of CDC42 were found in the inflamed IBD colon. Colonic Cdc42 depletion significantly reduced Lgr5+ IESCs, increased progenitors' hyperplasia, and induced mucosal inflammation, which led to crypt dysplasia. Colonic Cdc42 depletion markedly enhanced irradiation- or chemical-induced colitis. Depletion or inhibition of Cdc42 reduced colonic Lgr5+ IESC regeneration. In conclusion, depletion of Cdc42 reduces the IESC regeneration and IEC repair, leading to prolonged mucosal inflammation. Constitutive monogenic loss of Cdc42 induces mucosal inflammation, which could result in intestinal neoplasia in the context of aging.

Interplay between signal transducers and activators of transcription (STAT) proteins and cancer: involvement, therapeutic and prognostic perspective

Signal transducers and activators of transcription or STAT are proteins that consist of various transcription factors that are responsible for activating genes regarding cell proliferation, differentiation, and apoptosis. They commonly activate several cytokine, growth, or hormone factors via the JAK-STAT signaling pathway by tyrosine phosphorylation which are responsible for giving rise to numerous immune responses. Mutations within the Janus-Kinases (JAKs) or the STATs can set off the commencement of various malfunctions of the immune system of the body; carcinogenesis being an inevitable outcome. STATs are known to act as both oncogenes and tumor suppressor genes which makes it a hot topic of investigation. Various STATs related mechanisms are currently being investigated to analyze its potential of serving as a therapeutic base for numerous immune diseases and cancer; a deeper understanding of the molecular mechanisms involved in the signaling pathways can contribute to the same. This review will throw light upon each STAT member in causing cancer malignancies by affecting subsequent signaling pathways and its genetic and epigenetic associations as well as various inhibitors that could be used to target these pathways thereby devising new treatment options. The review will also focus upon the therapeutic advances made in cancers that most commonly affect people and discuss how STAT genes are identified as prognostic markers.

Chromosomal instability and inflammation: a catch-22 for cancer cells

Chromosomal instability (CIN), an increased rate of chromosomal segregation abnormalities, drives intratumor heterogeneity and affects most human cancers. In addition to chromosome copy number alterations, CIN results in chromosome(s) (fragments) being mislocalized into the cytoplasm in the form of micronuclei. Micronuclei can be detected by cGAS, a double-strand nucleic acid sensor, which will lead to the production of the second messenger 2'3'-cGAMP, activation of an inflammatory response, and downstream immune cell activation. However, the molecular network underlying the CIN-induced inflammatory response is still poorly understood. Furthermore, there is emerging evidence that cancers that display CIN circumvent this CIN-induced inflammatory response, and thus immune surveillance. The STAT1, STAT3, and NF-κB signaling cascades appear to play an important role in the CIN-induced inflammatory response. In this review, we discuss how these pathways are involved in signaling CIN in cells and how they are intertwined. A better understanding of how CIN is being signaled in cells and how cancer cells circumvent this is of the utmost importance for better and more selective cancer treatment.

Novel Histopathological Biomarkers in Prostate Cancer: Implications and Perspectives

Prostate cancer (PCa) is the second most frequently diagnosed cancer in men. Despite the significant progress in cancer diagnosis and treatment over the last few years, the approach to disease detection and therapy still does not include histopathological biomarkers. The dissemination of PCa is strictly related to the creation of a premetastatic niche, which can be detected by altered levels of specific biomarkers. To date, the risk factors for biochemical recurrence include lymph node status, prostate-specific antigen (PSA), PSA density (PSAD), body mass index (BMI), pathological Gleason score, seminal vesicle invasion, extraprostatic extension, and intraductal carcinoma. In the future, biomarkers might represent another prognostic factor, as discussed in many studies. In this review, we focus on histopathological biomarkers (particularly CD169 macrophages, neuropilin-1, cofilin-1, interleukin-17, signal transducer and activator of transcription protein 3 (STAT3), LIM domain kinase 1 (LIMK1), CD15, AMACR, prostate-specific membrane antigen (PSMA), Appl1, Sortilin, Syndecan-1, and p63) and their potential application in decision making regarding the prognosis and treatment of PCa patients. We refer to studies that found a correlation between the levels of biomarkers and tumor characteristics as well as clinical outcomes. We also hypothesize about the potential use of histopathological markers as a target for novel immunotherapeutic drugs or targeted radionuclide therapy, which may be used as adjuvant therapy in the future.

Plasma exosome-derived circGAPVD1 as a potential diagnostic marker for colorectal cancer

BACKGROUND

Although circular RNAs (circRNAs) have recently garnered interest as disease markers, they have been relatively poorly studied as a biomarker in colorectal cancer (CRC). In this study, we aimed to screen the exosome-derived circRNAs in CRC and explore their potential as diagnostic and prognostic biomarkers of CRC METHODS: Exosomes were extracted from the plasma using a kit and validated by immunoblotting, transmission electron microscopy, and particle size analysis. The microarray datasets were employed to identify differentially-expressed circRNAs from plasma exosomes. Real-time quantitative reverse transcription PCR (RT-qPCR) verified the results of the microarray analysis, and Receiver operating characteristic (ROC) curve revealed the diagnostic ability of a single circRNA. The Starbase combined with microT, miRmap, and RNA22 were used to establish a circRNA-miRNA-mRNA network. Gene ontology, Kyoto Encyclopedia of Genes, Genomes pathway enrichment analysis, and Gene Set Enrichment Analysis were applied to determine potential functions of the identified mRNAs RESULTS: Comparing the microarray of plasma exosome-derived circRNAs and the microarray downloaded from the GEO database, 15 candidate circRNAs with up-regulated expression were identified. RT-qPCR verified that hsa_circ_0003270 (circGAPVD1) was upregulated in CRC plasma exosomes. ROC analysis showed that circGAPVD1 in plasma exosomes has potential diagnostic value for CRC. The sensitivity and specificity of circGAPVD1 in the diagnosis of CRC were found to be 75.64 and 71.79%, respectively (area under ROC = 0.7662). Furthermore, the lymph node metastasis and TNM staging of patients were positively correlated with high expression of circGAPVD1. Combined with the ENCORI database and GEO datasets, we identified the circGAPVD1-related ceRNA network. The enrichment analysis revealed that key nodes in the ceRNA network participate in many important signaling pathways such as protein post-translational modifications CONCLUSION: Our results revealed the diagnostic efficiency of circGAPVD1 in plasma exosomes. The highly expressed circGAPVD1 is expected to be a novel diagnostic marker for CRC.

Interplay between Signaling Pathways and Tumor Microenvironment Components: A Paradoxical Role in Colorectal Cancer

The study of the tumor microenvironment (TME) has become an important part of colorectal cancer (CRC) research. Indeed, it is now accepted that the invasive character of a primary CRC is determined not only by the genotype of the tumor cells, but also by their interactions with the extracellular environment, which thereby orchestrates the development of the tumor. In fact, the TME cells are a double-edged sword as they play both pro- and anti-tumor roles. The interaction of the tumor-infiltrating cells (TIC) with the cancer cells induces the polarization of the TIC, exhibiting an antagonist phenotype. This polarization is controlled by a plethora of interconnected pro- and anti-oncogenic signaling pathways. The complexity of this interaction and the dual function of these different actors contribute to the failure of CRC control. Thus, a better understanding of such mechanisms is of great interest and provides new opportunities for the development of personalized and efficient therapies for CRC. In this review, we summarize the signaling pathways linked to CRC and their implication in the development or inhibition of the tumor initiation and progression. In the second part, we enlist the major components of the TME and discuss the complexity of their cells functions.

Association between the Methylation of CpG Islands in JAK-STAT Pathway-Related Genes and Colorectal Cancer

BACKGROUND

Aberrant promoter methylation of CpG islands plays an important role in carcinogenesis. However, the association between the DNA methylation of JAK-STAT pathway-related genes in peripheral blood leukocytes and colorectal cancer (CRC) susceptibility remains unclear.

METHODS

We conducted a case-control study of 403 patients with CRC and 419 cancer free controls, and the DNA methylation levels of JAK2, STAT1, STAT3, and SOCS3 in peripheral blood samples from all subjects were assessed using a methylation-sensitive high-resolution melting (MS-HRM) analysis.

RESULTS

Compared with controls, the methylation of the JAK2, STAT1 and SOCS3 genes increased the CRC risk (OR_adjusted=1.96, 95% CI, 1.12-3.41, P=0.01; OR_adjusted=5.37, 95% CI, 3.74-7.71, P<0.01; OR_adjusted=3.30, 95% CI, 1.58-6.87, P<0.01). In the multiple CpG site methylation (MCSM) analysis, a high MCSM value denoted an increased CRC risk (OR_adjusted=4.97, 95% CI, 3.34-7.37, P<0.01).

CONCLUSION

In peripheral blood, the methylation of JAK2, STAT1, and high levels of MCSM are promising biomarkers for CRC risk.

Correlation Analysis of Gene and Radiomic Features in Colorectal Cancer Liver Metastases

Colorectal cancer liver metastasis (CRLM) was one of the cancers with high mortality. Clinically, the target point was determined by invasive detection, which increased the suffering of patients and the cost of treatment. If the target point was found through the relationship between early radiomic information and genetic information, it was expected to assist doctors in diagnosing disease, formulating treatment plans, and reducing the pain and burden of patients. In this study, gene coexpression analysis and hub gene mining were first performed on the gene data; secondly, quantitative radiomic features were extracted from CT-enhanced radiomic data to obtain features highly correlated with CRLM; and finally, we analyzed the relationship between gene features and radiomic feature correlations by establishing a link between early radiomic features and gene sequencing and finding highly correlated expressions. This experiment demonstrated that radiomic features could be used to mine gene attributes. Based on the four previously identified genes (NRAS, KRAS, BRAF, and PIK3CA), we identified two novel genes, MAPK1 and STAT1, highly associated with CRLM. There were specific correlations between these 6 genes and radiomic features (shape_elongation, glcm, glszm, firstorder_10percentile, gradient, exponent_firstorder_Range, and gradient_glszm_SmallAreaLowGrayLevel). Therefore, this paper established the correlation between radiomic features and genes, and through radiomic features, we could find the genes associated with them, which was expected to achieve noninvasive prediction of liver metastasis.

Primary cilia contribute to the aggressiveness of atypical teratoid/rhabdoid tumors

Atypical teratoid/rhabdoid tumor (AT/RT) is a highly malignant brain tumor in infants that is characterized by loss of nuclear expression of SMARCB1 or SMARCA4 proteins. Recent studies show that AT/RTs comprise three molecular subgroups, namely AT/RT-TYR, AT/RT-MYC and AT/RT-SHH. The subgroups show distinct expression patterns of genes involved in ciliogenesis, however, little is known about the functional roles of primary cilia in the biology of AT/RT. Here, we show that primary cilia are present across all AT/RT subgroups with specific enrichment in AT/RT-TYR patient samples. Furthermore, we demonstrate that primary ciliogenesis contributes to AT/RT biology in vitro and in vivo. Specifically, we observed a significant decrease in proliferation and clonogenicity following disruption of primary ciliogenesis in AT/RT cell line models. Additionally, apoptosis was significantly increased via the induction of STAT1 and DR5 signaling, as detected by proteogenomic profiling. In a Drosophila model of SMARCB1 deficiency, concomitant knockdown of several cilia-associated genes resulted in a substantial shift of the lethal phenotype with more than 20% of flies reaching adulthood. We also found significantly extended survival in an orthotopic xenograft mouse model of AT/RT upon disruption of primary ciliogenesis. Taken together, our findings indicate that primary ciliogenesis or its downstream signaling contributes to the aggressiveness of AT/RT and, therefore, may constitute a novel therapeutic target.

Comprehensive analysis of the prognostic and immunotherapeutic implications of STAT family members in human colorectal cancer

Background: Colorectal cancer (CRC) is the third most prevalent cancer worldwide and the second leading cause of cancer mortality. Signal transducer and activator of transcription (STAT) proteins are a group of transcription factors implicated in cell signal transduction and gene transcription in several cancer types. However, the level of expression, genetic alterations, and biological function of different STATs, as well as their prognostic and immunotherapeutic value in CRC remain unclear.

Methods: The mRNA and protein expression levels, genetic alterations, prognostic value, gene–gene and protein–protein interaction networks, and biological function of STATs in CRC were studied using the GEPIA, HPA, cBioPortal, PrognoScan, Kaplan–Meier plotter, GeneMANIA, STRING, and Metascape databases. The expression of STATs in CRC was confirmed using immunohistochemistry (IHC). Finally, the relationship between STAT expression and immune infiltration as well as immunotherapy-associated indicators was also investigated.

Results: The expression levels of STAT2/5A/5B are downregulated in CRC, and the STAT1/3/4/5B expressions were significantly associated with the tumor stage of patients with CRC. The abnormal expression of STAT2/4/5B in patients with CRC is related to the prognosis of patients with CRC. The STATs and their neighboring proteins are primarily associated with lymphocyte activation, cytokine-mediated signaling pathways, positive regulation of immune response, regulation of cytokine production, and growth hormone receptor signaling pathways in cancer. The expression of STATs was significantly associated with immune infiltration and immunotherapy response-associated indicators.

Conclusion: This study may help further understand the molecular mechanism of CRC and provide new prognostic biomarkers and immunotherapy targets in patients with CRC.

The multi-kinase inhibitor afatinib serves as a novel candidate for the treatment of human uveal melanoma

PURPOSE

Uveal melanoma (UM) is the most common intraocular malignancy in adults with a poor prognosis and a high recurrence rate. Currently there is no effective treatment for UM. Multi-kinase inhibitors targeting dysregulated pro-tumorigenic signalling pathways have revolutionised anti-cancer treatment but, as yet, their efficacy in UM has not been established. Here, we identified the multi-kinase inhibitor afatinib as a highly effective agent that exerts anti-UM effects in in vitro, ex vivo and in vivo models.

METHODS

We assessed the anti-cancer effects of afatinib using cell viability, cell death and cell cycle assays in in vitro and ex vivo UM models. The signaling pathways involved in the anti-UM effects of afatinib were evaluated by Western blotting. The in vivo activity of afatinib was evaluated in UM xenograft models using tumour mass measurement, PET scan, immunohistochemical staining and TUNEL assays.

RESULTS

We found that afatinib reduced cell viability and activated apoptosis and cell cycle arrest in multiple established UM cell lines and in patient tumour-derived primary cell lines. Afatinib impaired cell migration and enhanced reproductive death in these UM cell models. Afatinib-induced cell death was accompanied by activation of STAT1 expression and downregulation of Bcl-xL and cyclin D1 expression, which control cell survival and cell cycle progression. Afatinib attenuated HER2-AKT/ERK/PI3K signalling in UM cell lines. Consistent with these observations, we found that afatinib suppressed tumour growth in UM xenografted mice.

CONCLUSION

Our data indicate that afatinib activates UM cell death and targets the HER2-mediated cascade, which modulates STAT1-Bcl-xL/cyclin D1 signalling. Thus, targeting HER2 with agents like afatinib may be a novel therapeutic strategy to treat UM and to prevent metastasis.

Targeting colon cancer stem cells using novel doublecortin like kinase 1 antibody functionalized folic acid conjugated hesperetin encapsulated chitosan nanoparticles

The cancer stem cell (CSC) hypothesis is an evolving oncogenesis concept. CSCs have a distinct ability to self-renew themselves and also give rise to a phenotypically diverse population of cells. Targeting CSCs represents a promising strategy for cancer treatment. Plant-derived compounds are potent in restricting the expansion of CSCs. DCLK1 has been already reported as a colon CSC specific marker. Nanoparticles can effectively inhibit multiple types of CSCs by targeting specific markers. We have synthesized DCLK1 functionalized folic acid conjugated hesperetin encapsulated chitosan nanoparticles (CFH-DCLK1), specifically to target CSCs. In this regard, we have performed proliferation assay, colony formation assay, cell migration assay, apoptosis assay, flow cytometry analysis, real-time RT- PCR and western blot analyses to determine the effect of CFH-DCLK1 and CFH nanoparticles in HCT116-colon cancer cells. In our study, we have determined the median inhibitory concentration (IC50) of CFH (47.8 µM) and CFH-DCLK1 (4.8 µM) nanoparticles in colon cancer cells. CFH-DCLK1 nanoparticles induced apoptosis and inhibited the migration and invasion of colon cancer cells. Real time PCR and western blot results have demonstrated that the treatment with CFH-DCLK1 nanoparticles significantly reduced the expression of CSC markers such as DCLK1, STAT1 and NOTCH1 compared to the CFH alone in HCT116 colon cancer cells. Finally, in the 3D spheroid model, CFH-DCLK1 nanoparticles significantly inhibited the colonosphere growth. Overall, our results highlight the effectiveness of CFH-DCLK1 nanoparticles in targeting the colon cancer cells and CSCs. This study would lead to the development of therapies targeting both cancer cells and CSCs simultaneously using nanoformulated drugs, which could bring changes in the current cancer treatment strategies.

Whole exome sequencing identifies novel germline variants of SLC15A4 gene as potentially cancer predisposing in familial colorectal cancer

About 15% of colorectal cancer (CRC) patients have first-degree relatives affected by the same malignancy. However, for most families the cause of familial aggregation of CRC is unknown. To identify novel high-to-moderate-penetrance germline variants underlying CRC susceptibility, we performed whole exome sequencing (WES) on four CRC cases and two unaffected members of a Polish family without any mutation in known CRC predisposition genes. After WES, we used our in-house developed Familial Cancer Variant Prioritization Pipeline and identified two novel variants in the solute carrier family 15 member 4 (SLC15A4) gene. The heterozygous missense variant, p. Y444C, was predicted to affect the phylogenetically conserved PTR2/POT domain and to have a deleterious effect on the function of the encoded peptide/histidine transporter. The other variant was located in the upstream region of the same gene (GRCh37.p13, 12_129308531_C_T; 43 bp upstream of transcription start site, ENST00000266771.5) and it was annotated to affect the promoter region of SLC15A4 as well as binding sites of 17 different transcription factors. Our findings of two distinct variants in the same gene may indicate a synergistic up-regulation of SLC15A4 as the underlying genetic cause and implicate this gene for the first time in genetic inheritance of familial CRC.

Identification of a prognostic signature in colorectal cancer using combinatorial algorithm-driven analysis

Colorectal carcinoma is one of the most common types of malignancy and a leading cause of cancer‐related death. Although clinicopathological parameters provide invaluable prognostic information, the accuracy of prognosis can be improved by using molecular biomarker signatures. Using a large dataset of immunohistochemistry‐based biomarkers (n = 66), this study has developed an effective methodology for identifying optimal biomarker combinations as a prognostic tool. Biomarkers were screened and assigned to related subsets before being analysed using an iterative algorithm customised for evaluating combinatorial interactions between biomarkers based on their combined statistical power. A signature consisting of six biomarkers was identified as the best combination in terms of prognostic power. The combination of biomarkers (STAT1, UCP1, p‐cofilin, LIMK2, FOXP3, and ICOS) was significantly associated with overall survival when computed as a linear variable (χ² = 53.183, p < 0.001) and as a cluster variable (χ² = 67.625, p < 0.001). This signature was also significantly independent of age, extramural vascular invasion, tumour stage, and lymph node metastasis (Wald = 32.898, p < 0.001). Assessment of the results in an external cohort showed that the signature was significantly associated with prognosis (χ² = 14.217, p = 0.007). This study developed and optimised an innovative discovery approach which could be adapted for the discovery of biomarkers and molecular interactions in a range of biological and clinical studies. Furthermore, this study identified a protein signature that can be utilised as an independent prognostic method and for potential therapeutic interventions.

High-Throughput Profiling of Colorectal Cancer Liver Metastases Reveals Intra- and Inter-Patient Heterogeneity in the EGFR and WNT Pathways Associated with Clinical Outcome

Simple Summary

Tumor heterogeneity can greatly influence therapy outcome and patient survival. In this study, we aimed at unraveling inter- and intra-patient heterogeneity of colorectal cancer liver metastases (CRLM). To this end, we comprehensively characterized CRLM using state-of-the-art high-throughput technologies combined with bioinformatics analyses. We found a high degree of inter- and intra-patient heterogeneity among the metastases, in particular in genes of the WNT and EGFR pathways. Through analyzing the master regulators and effectors associated with the regulation of these genes, we identified a specific gene signature that was highly expressed in a large cohort of colorectal cancer patients and associated with clinical outcome.

Abstract

Seventy percent of patients with colorectal cancer develop liver metastases (CRLM), which are a decisive factor in cancer progression. Therapy outcome is largely influenced by tumor heterogeneity, but the intra- and inter-patient heterogeneity of CRLM has been poorly studied. In particular, the contribution of the WNT and EGFR pathways, which are both frequently deregulated in colorectal cancer, has not yet been addressed in this context. To this end, we comprehensively characterized normal liver tissue and eight CRLM from two patients by standardized histopathological, molecular, and proteomic subtyping. Suitable fresh-frozen tissue samples were profiled by transcriptome sequencing (RNA-Seq) and proteomic profiling with reverse phase protein arrays (RPPA) combined with bioinformatic analyses to assess tumor heterogeneity and identify WNT- and EGFR-related master regulators and metastatic effectors. A standardized data analysis pipeline for integrating RNA-Seq with clinical, proteomic, and genetic data was established. Dimensionality reduction of the transcriptome data revealed a distinct signature for CRLM differing from normal liver tissue and indicated a high degree of tumor heterogeneity. WNT and EGFR signaling were highly active in CRLM and the genes of both pathways were heterogeneously expressed between the two patients as well as between the synchronous metastases of a single patient. An analysis of the master regulators and metastatic effectors implicated in the regulation of these genes revealed a set of four genes (SFN, IGF2BP1, STAT1, PIK3CG) that were differentially expressed in CRLM and were associated with clinical outcome in a large cohort of colorectal cancer patients as well as CRLM samples. In conclusion, high-throughput profiling enabled us to define a CRLM-specific signature and revealed the genes of the WNT and EGFR pathways associated with inter- and intra-patient heterogeneity, which were validated as prognostic biomarkers in CRC primary tumors as well as liver metastases.

Proteasome inhibitors restore the STAT1 pathway and enhance the expression of MHC class I on human colon cancer cells

BACKGROUND

A new strategy, particularly a novel combination, for immunotherapy in microsatellite stable metastatic colorectal cancer (mCRC) treatment needs to be formulated. Studies on the interferon-γ (IFN-γ)/ Janus kinase (JAK)/ signal transducer and activator of transcription (STAT)1 pathway provide new directions in this regard.

METHODS

Our study applies three colon cancer cell lines, including microsatellite stable (MSS) cell lines, which are SW480 and SW620, and microsatellite instability-high (MSI-H) cell line, which is DLD-1. We compared the expressions of immune surface markers on colon cancer cells in response to IFN-γ. We elucidated these mechanisms, which involved the upregulation of immune surface markers. Furthermore, we examined real-world clinical samples using the PerkinElmer Opal multiplex system and NanoString analysis.

RESULTS

We established that the baseline expression of major histocompatibility complex (MHC) class I alleles and programmed death-ligand 1 (PD-L1) were generally low in cell line models. The immune surface markers were significantly increased after IFN-γ stimulation on SW480 but were notably unresponsive on the SW620 cell line. We discovered that STAT1 and phosphorylated STAT1 (pSTAT1) were downregulated in the SW620 cell line. We verified that the STAT1/pSTAT1 could be restored through the application of proteasome inhibitors, especially bortezomib. The expression of MHC class I as downstream signals of STAT1 was also up-regulated by proteasome inhibitors. The similar results were reproduced in DLD-1 cell line, which was also initially unresponsive to IFN-γ. In real-world samples of patients with mCRC, we found that higher STAT1 expression in tumor cells was strongly indicative of a highly immunogenic microenvironment, with significantly higher expression levels of MHC class I and PD-L1, not only on tumor cells but also on non-tumor cells. Furthermore, tumor infiltrating lymphocytes (TILs) were increased in the positive-STAT1 group. Through NanoString analysis, we confirmed that the mRNA expressions of IFN-γ, human leukocyte antigen (HLA)-A, HLA-E, and HLA-G were also significantly higher in the positive-STAT1 group than those in the negative-STAT1 group.

CONCLUSION

Our study provides a novel rationale for the addition of bortezomib, a proteasome inhibitor, into new immunotherapy combinations.

Merkel cell polyomavirus-negative Merkel cell carcinoma is associated with JAK-STAT and MEK-ERK pathway activation

Merkel cell polyomavirus (MCPyV) is monoclonally integrated into the genomes of approximately 80% of Merkel cell carcinomas (MCCs). While the presence of MCPyV affects the clinicopathological features of MCC, the molecular mechanisms of MCC pathogenesis after MCPyV infection are unclear. This study investigates the association between MCPyV infection and activation of the MEK-ERK and JAK-STAT signaling pathways in MCC to identify new molecular targets for MCC treatment. The clinicopathological characteristics of 30 MCPyV-positive and 20 MCPyV-negative MCC cases were analyzed. The phosphorylation status of MEK, ERK, JAK, and STAT was determined by immunohistochemical analysis. The activation status of the MEK-ERK and JAK-STAT pathways and the effects of a JAK inhibitor (ruxolitinib) was analyzed in MCC cell lines. Immunohistochemically, the expression of pJAK2 (P = .038) and pERK1/2 (P = .019) was significantly higher in MCPyV-negative than in MCPyV-positive MCCs. Male gender (hazard ratio [HR] 2.882, P = .039), older age (HR 1.137, P < .001), negative MCPyV status (HR 0.324, P = .013), and advanced cancer stage (HR 2.672, P = .041) were identified as unfavorable prognostic factors; however, the phosphorylation states of JAK2, STAT3, MEK1/2, and ERK1/2 were unrelated to the prognosis. The inhibition of cell proliferation by ruxolitinib was greater in MCPyV-negative MCC cell lines than in an MCPyV-positive MCC cell line. The expression of pERK1/2 and pMEK was higher in MCPyV-negative than in MCPyV-positive cell lines. These results suggest that activation of the JAK2 and MEK-ERK pathways was more prevalent in MCPyV-negative than in MCPyV-positive MCC and the JAK inhibitor ruxolitinib inhibited MEK-ERK pathway activation. Consequently, the JAK-STAT and MEK-ERK signaling pathways may be potential targets for MCPyV-negative MCC treatment.

A Recurrent STAT5BN642H Driver Mutation in Feline Alimentary T Cell Lymphoma

Alimentary lymphomas arising from T cells are rare and aggressive malignancies in humans. In comparison, they represent the most common anatomical form of lymphoma in cats. Due to the low prevalence in humans, the underlying pathomechanism for these diseases is poorly characterised, limiting experimental analysis and therapeutic exploration. To date, activating mutations of the JAK/STAT core cancer pathway and particularly the STAT5B oncoprotein have been identified in human enteropathy-associated T cell lymphoma. Here, we describe a high homology of human and feline STAT3 and STAT5B proteins and strong conservation at the genomic level. Analysis of 42 samples of feline T cell alimentary lymphoma reveals broad activation of STAT3 and STAT5B. Screening for known activating mutations in STAT3 or STAT5B identifies the presence of the STAT5BN642H driver mutation in feline enteropathy-associated T cell lymphoma in 7 out of 42 (16.67%) samples in total. Regarding lymphoma subtypes, the majority of mutations with 5 out of 17 (29.41%) cases were found in feline enteropathy-associated lymphoma type II (EATL II). This identification of an oncogenic STAT5B driver mutation in felines recapitulates the genetic situation in the corresponding human disease, thereby establishing the cat as a potential new model for a rare and incurable human T cell disease.

Root Bark of Morus Alba L. Induced p53-Independent Apoptosis in Human Colorectal Cancer Cells by Suppression of STAT3 Activity

The root bark of Morus alba L. (MA) used in traditional oriental medicine exerts various bioactivities including anticancer effects. In this study, we investigated the molecular mechanism underlying the methylene chloride extract of MA (MEMA)-induced apoptosis in colorectal cancer (CRC) cells. We observed that MEMA decreased cell viability and colony formation in both HCT116 p53+/+ cells and HCT116 p53-/- cells. In addition, MEMA increased the sub-G1 phase DNA content, the annexin V-positive cell population, and the expression of apoptosis marker proteins in both cell lines, indicating that MEMA induced apoptosis regardless of the p53 status. Interestingly, the phosphorylation level, transcriptional activity, and target genes expression of signal transducer and activator of transcription 3 (STAT3) were commonly decreased by MEMA. The overexpression of constitutively active STAT3 in HCT116 cells reversed MEMA-induced apoptosis, demonstrating that MEMA-triggered apoptosis was mediated by the inactivation of STAT3. Taken together, we suggest that MEMA can be applied not only to p53 wild-type CRC in the early stages but also to p53-mutant advanced CRC with hyperactivated STAT3. Even though a wide range of studies are required to validate the anticancer effects of MEMA, we propose MEMA as a novel material for the treatment of CRC.

Comprehensive analyses of potential key genes in active tuberculosis: A systematic review

BACKGROUND

Tuberculosis (TB) is a global health problem that brings us numerous difficulties. Diverse genetic factors play a significant role in the progress of TB disease. However, still no key genes for TB susceptibility have been reported. This study aimed to identify the key genes of TB through comprehensive bioinformatics analysis.

METHODS

The series microarray datasets from the gene expression omnibus (GEO) database were analyzed. We used the online tool GEO2R to filtrate differentially expressed genes (DEGs) between TB and health control. Database for annotation can complete gene ontology function analysis as well as Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. Protein-protein interaction (PPI) networks of DEGs were established by STRING online tool and visualized by Cytoscape software. Molecular Complex Detection can complete the analysis of modules in the PPI networks. Finally, the significant hub genes were confirmed by plug-in Genemania of Cytoscape, and verified by the verification cohort and protein test.

RESULTS

There are a total of 143 genes were confirmed as DEGs, containing 48 up-regulated genes and 50 down-regulated genes. The gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis show that upregulated DEGs were associated with cancer and phylogenetic, whereas downregulated DEGs mainly concentrate on inflammatory immunity. PPI networks show that signal transducer and activator of transcription 1 (STAT1), guanylate binding protein 5 (GBP5), 2'-5'-oligoadenylate synthetase 1 (OAS1), catenin beta 1 (CTNNB1), and guanylate binding protein 1 (GBP1) were identified as significantly different hub genes.

CONCLUSION

We conclude that these genes, including TAT1, GBP5, OAS1, CTNNB1, GBP1 are a candidate as potential core genes in TB and treatment of TB in the future.

STAT1 Is Required for Decreasing Accumulation of Granulocytic Cells via IL-17 during Initial Steps of Colitis-Associated Cancer

Signal transducer and activator of transcription 1 (STAT1) acts as a tumor suppressor molecule in colitis-associated colorectal cancer (CAC), particularly during the very early stages, modulating immune responses and controlling mechanisms such as apoptosis and cell proliferation. Previously, using an experimental model of CAC, we reported increased intestinal cell proliferation and faster tumor development, which were consistent with more signs of disease and damage, and reduced survival in STAT1^-/- mice, compared with WT counterparts. However, the mechanisms through which STAT1 might prevent colorectal cancer progression preceded by chronic inflammation are still unclear. Here, we demonstrate that increased tumorigenicity related to STAT1 deficiency could be suppressed by IL-17 neutralization. The blockade of IL-17 in STAT1^-/- mice reduced the accumulation of CD11b+Ly6C^lowLy6G+ cells resembling granulocytic myeloid-derived suppressor cells (MDSCs) in both spleen and circulation. Additionally, IL-17 blockade reduced the recruitment of neutrophils into intestinal tissue, the expression and production of inflammatory cytokines, and the expression of intestinal STAT3. In addition, the anti-IL-17 treatment also reduced the expression of Arginase-1 and inducible nitric oxide synthase (iNOS) in the colon, both associated with the main suppressive activity of MDSCs. Thus, a lack of STAT1 signaling induces a significant change in the colonic microenvironment that supports inflammation and tumor formation. Anti-IL-17 treatment throughout the initial stages of CAC related to STAT1 deficiency abrogates the tumor formation possibly caused by myeloid cells.

Bioinformatics Analysis of Expression Profiles and Prognostic Values of the Signal Transducer and Activator of Transcription Family Genes in Glioma

Signal transducer and activator of transcription (STAT) family genes—of which there are seven members: STAT1, STAT2, STAT3, STAT4, STAT5A, STAT5B, and STAT6—have been associated with the progression of multiple cancers. However, their prognostic values in glioma remain unclear. In this study, we systematically investigated the expression, the prognostic value, and the potential mechanism of the STAT family genes in glioma. The expression of STAT1/2/3/5A/6 members were significantly higher and positively correlated with IDH mutations, while the expression of STAT5B was lower and negatively correlated with IDH mutations in glioma. Survival analysis indicated that the upregulation of STAT1/2/3/5A/6 and downregulation of STAT5B expression was associated with poorer overall survival in glioma. Joint effects analysis of STAT1/2/3/5A/5B/6 expression suggested that the prognostic value of the group was more significant than that of each individual gene. Thus, we constructed a risk score model to predict the prognosis of glioma. The receiver operating characteristic curve and calibration curves showed good performance as prognostic indicators in both TCGA (The Cancer Genome Atlas) and the CGGA (Chinese Glioma Genome Atlas) databases. Furthermore, we analyzed the correlation between STAT expression with immune infiltration in glioma. The Protein–protein interaction network and enrichment analysis showed that STAT members and co-expressed genes mainly participated in signal transduction activity, Hepatitis B, the Jak-STAT signaling pathway, transcription factor activity, sequence-specific DNA binding, and the cytokine-mediated signaling pathway in glioma. In summary, our study analyzed the expression, prognostic values, and biological roles of the STAT gene family members in glioma, based on which we developed a new risk score model to predict the prognosis of glioma more precisely.

Snail Overexpression Alters the microRNA Content of Extracellular Vesicles Released from HT29 Colorectal Cancer Cells and Activates Pro-Inflammatory State In Vivo

Simple Summary

Knowledge of the factors that help migration of carcinoma cells is important for prevention of metastasis. Cancer cells release small particles, extracellular vesicles (EVs) that contain such factors. The aim of this study was to assess if the content of EVs changes through different stages of colorectal cancer (CRC) and evaluate how this process affects cancer progression in vivo in mouse CRC model. We found that EVs released from cells that have migratory properties contain different factors then EVs released from original tumor cells. We also show here that EVs can be incorporated into other cells that facilitate metastasis and change their properties depending on the EVs content. The content of cell-released EVs may also serve as a biomarker that denotes the stage of CRC and may be a target to prevent cancer progression.

Abstract

During metastasis, cancer cells undergo phenotype changes in the epithelial-mesenchymal transition (EMT) process. Extracellular vesicles (EVs) released by cancer cells are the mediators of intercellular communication and play a role in metastatic process. Knowledge of factors that influence the modifications of the pre-metastatic niche for the migrating carcinoma cells is important for prevention of metastasis. We focus here on how cancer progression is affected by EVs released from either epithelial-like HT29-cells or from cells that are in early EMT stage triggered by Snail transcription factor (HT29-Snail). We found that EVs released from HT29-Snail, as compared to HT29-pcDNA cells, have a different microRNA profile. We observed the presence of interstitial pneumonias in the lungs of mice injected with HT29-Snail cells and the percent of mice with lung inflammation was higher after injection of HT29-Snail-EVs. Incorporation of EVs released from HT29-pcDNA, but not released from HT29-Snail, leads to the increased secretion of IL-8 from macrophages. We conclude that Snail modifications of CRC cells towards more invasive phenotype also alter the microRNA cargo of released EVs. The content of cell-released EVs may serve as a biomarker that denotes the stage of CRC and EVs-specific microRNAs may be a target to prevent cancer progression.

Phosphorylated transducer and activator of transcription-3 (pSTAT3) immunohistochemical expression in paired primary and metastatic colorectal cancer

BACKGROUND

Signal Transducer and Activator of Transcription-3 (STAT3) mediates cellular functions. We assessed the IHC expression of phosphorylated STAT3 (pSTAT3) in paired primary tumors and liver metastases in patients with advanced stage colorectal cancer (CRC).

METHODS

We included patients with tissue blocks available from both the primary CRC and a surgically resected liver metastasis. The IHC pSTAT3 expression agreement was measured using Cohen's kappa statistic.

RESULTS

The study included 103 patients, 55% male, median age was 64. 43% tumors originated in rectum, and 63% of the primary tumors were synchronous. Expression of pSTAT3 was 76% in liver metastases and 71% in primary tumors. A difference in pSTAT3 staining between the primary tumor and liver metastases was noted in 64%. There was lost expression of pSTAT3 in the liver metastases in 28% and gained expression in 36% of cases compared to the primary. The kappa statistic comparing agreement between staining patterns of the primary tumors and liver metastases was a "less-than-chance", at -0.02. Median survival was 4.9 years, with no difference in survival outcomes by pSTAT3 expression in the primary tumor or liver metastases.

DISCUSSION

STAT3 is not a prognostic marker in the selective setting of metastatic CRC to liver, but it may remain a potential therapeutic target given most liver metastases expressed pSTAT3. Discordant pSTAT3 expression in between primary tumors and paired liver metastases suggests that use of this class of drug to treat liver predominant metastatic colorectal cancer in a biomarker-driven approach may require confirmatory liver tumor biopsy.

Role of the JAK/STAT Pathway in Cervical Cancer: Its Relationship with HPV E6/E7 Oncoproteins

The janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway is associated with the regulation of essential cellular mechanisms, such as proliferation, invasion, survival, inflammation, and immunity. Aberrant JAK/STAT signaling contributes to cancer progression and metastatic development. STAT proteins play an essential role in the development of cervical cancer, and the inhibition of the JAK/STAT pathway may be essential for enhancing tumor cell death. Persistent activation of different STATs is present in a variety of cancers, including cervical cancer, and their overactivation may be associated with a poor prognosis and poor overall survival. The oncoproteins E6 and E7 play a critical role in the progression of cervical cancer and may mediate the activation of the JAK/STAT pathway. Inhibition of STAT proteins appears to show promise for establishing new targets in cancer treatment. The present review summarizes the knowledge about the participation of the different components of the JAK/STAT pathway and the participation of the human papillomavirus (HPV) associated with the process of cellular malignancy.

Expression of STAT1 is positively correlated with PD-L1 in human ovarian cancer

Signal transducer and activator of transcription 1 (STAT1) is related to the immune microenvironment of tumorigenesis. The programmed cell death 1 (PD-1) and its ligand (PD-L1) have been reported to be important in immunotherapy by mediating tumor immune evasion. Blocking the PD-1/PD-L1 pathway can restore the endogenous anti-tumor immune response. This study aimed to examine the expression of STAT1, PD-1, and PD-L1 and the correlation between selected markers in human epithelial ovarian cancer (EOC). The results showed that malignant tumors contained more STAT1, PD-1, and PD-L1 positive cells. The expression of STAT1 and PD-L1 was associated with age, whereas PD-1 and PD-L1 associated with histopathological type, in patients with ovarian tumors. Moreover, the expression of STAT1 was found to be associated with disease stages and the grade of serous carcinoma. STAT1 expression was higher in OC cells than normal ovarian surface epithelial cells and was positively correlated with PD-L1 expression. The knockdown of STAT1 decreased PD-L1 expression, whereas overexpression of STAT1 increased PD-L1 expression. Furthermore, the expression of STAT1, PD-1, and PD-L1 was lower in paclitaxel-resistant cells than sensitive cells. Finally, STAT1 affected the overall survival and progression-free survival of patients with EOC. These findings suggest that STAT1, PD-1, and PD-L1 are the tissue markers of EOC and imply the possibility that the high level of STAT1, PD-1, and PD-L1 may favor the checkpoint immunotherapy in patients with EOC, but may have a limit in paclitaxel-resistant patients because of the low expression of STAT1, PD-1, and PD-L1 in paclitaxel-resistant cells.

Repurposing of niclosamide as a STAT3 inhibitor to enhance the anticancer effect of chemotherapeutic drugs in treating colorectal cancer

AIMS

Colorectal cancer (CRC) is the third most common cancer worldwide. Mutation of various cell signaling molecules or aberrant activation of signaling pathways leads to poor response to chemotherapy in CRC. Signal transducer and activator of transcription protein 3 (STAT3) is an important signaling molecule, which plays crucial roles in regulating cell survival and growth. In this study, the potentitation of chemotherapy by putative STAT3 inhibitors for treating CRC was investigated.

MAIN METHODS

A few putative STAT3 inhibitors were investigated. Niclosamide, originally indicated for the treatment of tapeworm infection, was chosen for further investigation in five CRC cell lines (HCT116, HT29, HCC2998, LoVo and SW480). Western blot analysis was used to evaluate the expression of STAT3/phospho-STAT3 and its downstream targets. Sulforhodamine B assay was used to evaluate the cytotoxicity of drug combinations. Flow cytometric assays were used to investigate the apoptotic and cell cycle effect.

KEY FINDINGS

Niclosamide was found to inhibit expression and activation of STAT3 in a concentration- and time-dependent manner, thereby downregulating STAT3 downstream targets including survivin and cyclin-D1 to induce apoptosis and cell cycle arrest. When combined with niclosamide or specific STAT3 inhibitor (C188-9), the cytotoxicity and DNA damage response from SN38 (the active metabolite from irinotecan) were significantly enhanced. The sequential exposure of SN38 followed by niclosamide was found to be the most potent treatment sequence for the drug combination.

SIGNIFICANCE

Niclosamide represents a promising candidate for repurposing to potentiate the anticancer activity of chemotherapeutic drugs.

Novel Proteome Extraction Method Illustrates a Conserved Immunological Signature of MSI-H Colorectal Tumors

Using a simple, environment friendly proteome extraction (TOP), we were able to optimize the analysis of clinical samples. Using our TOP method we analyzed a clinical cohort of microsatellite stable (MSS) and unstable (MSI-H) colorectal carcinoma (CRC). We identified a tumor cell specific, STAT1-centered, immune signature expressed by the MSI-H tumor cells. We then showed that long, but not short, exposure to Interferon-γ induces a similar signature in vitro We identified 10 different temporal protein expression patterns, classifying the Interferon-γ protein temporal regulation in CRC. Our data sheds light on the changes that tumor cells undergo under long-term immunological pressure in vivo, the importance of STAT proteins in specific biological scenarios. The data generated could help find novel clinical biomarkers and therapeutic approaches.

Biomarkers in previous histologically negative prostate biopsies can be helpful in repeat biopsy decision-making processes

To evaluate whether the addition of biomarkers to traditional clinicopathological parameters may help to increase the accurate prediction of prostate re‐biopsy outcome. A training cohort with 98 patients and a validation cohort with 72 patients were retrospectively recruited into our study. Immunohistochemical analysis was used to evaluate the immunoreactivity of a group of biomarkers in the initial negative biopsy normal‐looking tissues of the training and validation cohorts. p‐STAT3, Mcm2, and/or MSR1 were selected out of 10 biomarkers to construct a biomarker index for predicting cancer and high‐grade prostate cancer (HGPCa) in the training cohort based on the stepwise logistic regression analysis; these biomarkers were then validated in the validation cohort. In the training cohort study, we found that the biomarker index was independently associated with the re‐biopsy outcomes of cancer and HGPCa. Moreover supplementing the biomarker index with traditional clinical‐pathological parameters can improve the area under the receiver operating characteristic curve of the model from 0.722 to 0.842 and from 0.735 to 0.842, respectively, for predicting cancer and HGPCa at re‐biopsy. In the decision‐making analysis, we found the model supplemented with the biomarker index can improve patients’ net benefit. The application of the model to clinical practice, at a 10% risk threshold, would reduce the number of biopsies by 34.7% while delaying the diagnosis of 7.8% cancers and would reduce the number of biopsies by 73.5% while delaying the diagnosis of 17.8% HGPCas. Taken together, supplementing the biomarker index with clinicopathological parameters may help urologists in re‐biopsy decision‐making processes.

Tn Antigen Expression Contributes to an Immune Suppressive Microenvironment and Drives Tumor Growth in Colorectal Cancer

Expression of the tumor-associated glycan Tn antigen (αGalNAc-Ser/Thr) has been correlated to poor prognosis and metastasis in multiple cancer types. However, the exact mechanisms exerted by Tn antigen to support tumor growth are still lacking. One emerging hallmark of cancer is evasion of immune destruction. Although tumor cells often exploit the glycosylation machinery to interact with the immune system, the contribution of Tn antigen to an immunosuppressive tumor microenvironment has scarcely been studied. Here, we explored how Tn antigen influences the tumor immune cell composition in a colorectal cancer (CRC) mouse model. CRISPR/Cas9-mediated knock out of the C1galt1c1 gene resulted in elevated Tn antigen levels on the cell surface of the CRC cell line MC38 (MC38-Tn^high). RNA sequencing and subsequent GO term enrichment analysis of our Tn^high glycovariant not only revealed differences in MAPK signaling and cell migration, but also in antigen processing and presentation as well as in cytotoxic T cell responses. Indeed, MC38-Tn^high tumors displayed increased tumor growth in vivo, which was correlated with an altered tumor immune cell infiltration, characterized by reduced levels of cytotoxic CD8⁺ T cells and enhanced accumulation of myeloid-derived suppressor cells. Interestingly, no systemic differences in T cell subsets were observed. Together, our data demonstrate for the first time that Tn antigen expression in the CRC tumor microenvironment affects the tumor-associated immune cell repertoire.

Emerging role of microbiota in immunomodulation and cancer immunotherapy

Gut microbiota is emerging as a key modulator of the immune system. Alteration of gut microbiota impacts functioning of the immune system and pathophysiology of several diseases, including cancer. Growing evidence indicates that gut microbiota is not only involved in carcinogenesis but also has an impact on the efficacy and toxicity of cancer therapy. Recently, several pre-clinical and clinical studies across diverse cancer types reported the influence of gut microbiota on the host immune response to immunotherapy. Advancement in our understanding of the mechanism behind microbiota-mediated modulation of immune response is paramount for their utilization as cancer therapeutics. These microbial therapies in combination with conventional immunotherapeutic methods have the potential to transform the pre-existing treatment strategies to personalized cancer therapy. In this review, we have summarized the current status of research in the field and discussed the role of microbiota as an immune system modulator in context of cancer and their impact on immunotherapy.

Highly expressed STAT1 contributes to the suppression of stemness properties in human paclitaxel-resistant ovarian cancer cells

Signal transducer and activator of transcription-1 (STAT1) is an important factor in various cellular processes. The cancer stem cell (CSC) is considered as a tumor-initiating cell that drives the inner hierarchy in many cancers including epithelial ovarian cancer (EOC). Here, we explored for the first time the regulation of STAT1 on stemness properties in chemoresistant EOC cells. The paclitaxel (PTX)-resistant EOC cell line (OV3R-PTX) was derived from PTX-sensitive OVCAR-3 cells treated by the PTX regimen. A single cell clone OV3R-PTX-B4 was selected by fluorescence-activated cell sorting. PTX-resistant cells grew slowly in conventional 2D and 3D cultures, but tumor xenograft with PTX-resistant cells grew fast in nude mice. Interestingly, OV3R-PTX-B4 cells shared the characteristics of CSCs and stemness properties were found to be increased in the non-adherent spheroid culture system. The PTX-resistant cells had a high expression of CSC-related markers and low expression of STAT1 that had a high methylation level of CpG in its promoter region. Overexpressed STAT1 suppressed stemness properties, cell proliferation, and colony formation and favored the overall survival of patients with EOC. In summary, these data indicate a regulatory mechanism of STAT1 underlying drug resistance and provide a potential therapeutic application for EOC patients with PTX resistance.

STAT3: A key signaling molecule for converting cold to hot tumors

Tumors can be classified as cold or hot according to the degree of immune cell infiltration into tumor tissues; cold tumors are insensitive to either chemotherapy or immunotherapy and are associated with poor prognosis. Recent studies have shown that STAT3 signaling molecules hinder the conversion of cold to hot tumors by regulating immunosuppressive molecule secretion and immunosuppressive cell functions. This review aims to present the most recent studies on how STAT3 regulates cold tumor formation and discuss its research status in cancer therapy. We also present insight for designing new therapeutic strategies to "heat" tumors and provide a reference for tumor immunotherapy.

Significance of STAT3 in Immune Infiltration and Drug Response in Cancer

Signal transducer and activator of transcription 3 (STAT3) is a transcription factor and regulates tumorigenesis. However, the functions of STAT3 in immune and drug response in cancer remain elusive. Hence, we aim to reveal the impact of STAT3 in immune infiltration and drug response comprehensively by bioinformatics analysis. The expression of STAT3 and its relationship with tumor stage were explored by Tumor Immune Estimation Resource (TIMER), Human Protein Altas (HPA), and UALCAN databases. The correlations between STAT3 and immune infiltration, gene markers of immune cells were analyzed by TIMER. Moreover, the association between STAT3 and drug response was evaluated by the Cancer Cell Line Encyclopedia (CCLE) and Cancer Therapeutics Response Portal (CTRP). The results suggested that the mRNA transcriptional level of STAT3 was lower in tumors than normal tissues and mostly unrelated to tumor stage. Besides, the protein expression of STAT3 decreased in colorectal and renal cancer compared with normal tissues. Importantly, STAT3 was correlated with immune infiltration and particularly regulated tumor-associated macrophage (TAM), M2 macrophage, T-helper 1 (Th1), follicular helper T (Treg), and exhausted T-cells. Remarkably, STAT3 was closely correlated with the response to specified inhibitors and natural compounds in cancer. Furthermore, the association between STAT3 and drug response was highly cell line type dependent. Significantly, the study provides thorough insight that STAT3 is associated with immunosuppression, as well as drug response in clinical treatment.

Predicting STAT1 as a prognostic marker in patients with solid cancer

Background:

Aberrant activities of signal transducer and activator of transcription 1 (STAT1) have been implicated in cancer development. However, the prognostic value of STAT1 remains unclear. This report identified the role of STAT1 in prognosis in patients with solid cancer through open literature and The Cancer Genome Atlas (TCGA) database.

Methods:

Published articles were obtained from PubMed, Web of Science, and Embase databases according to a search strategy up to October 2019. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were extracted to assess the prognostic factors of patients. TCGA datasets were used to explore the prognostic value of STAT1 in various cancers.

Results:

A total of 15 studies incorporating 2839 patients with solid cancers were included. Pooled data showed that overexpressed STAT1 favored long overall survival (OS) (HR = 0.604, 95% CI = 0.431–0.846, p = 0.003) and disease-specific survival (DSS) (HR = 0.650, 95% CI = 0.512–0.825, p = 0.000). In subgroup analyses, highly expressed STAT1 was correlated with long OS of patients with high-grade serous ovarian cancer and oral squamous cell carcinoma. Data extracted from TCGA datasets unveiled that STAT1 expression was significantly higher in 12 cancers (e.g. bladder and breast) than their adjacent normal tissues. Again, highly expressed STAT1 favored long OS of patients with ovarian cancer as well as rectum adenocarcinoma, sarcoma, and skin cutaneous melanoma. However, in renal carcinoma, brain lower grade glioma, lung adenocarcinoma, and pancreatic cancer, highly expressed STAT1 was correlated with poor OS of patients. Particularly in renal carcinoma, increased STAT1 expression was associated with high grade, later stage, large tumor size, and lymph node and distant metastasis.

Conclusion:

STAT1 has been identified to have prognostic value in patients with solid cancer. Highly expressed STAT1 may predict prognosis in cancer patients based on their tumor types.

STAT3: Versatile Functions in Non-Small Cell Lung Cancer

Signal Transducer and Activator of Transcription 3 (STAT3) activation is frequently found in non-small cell lung cancer (NSCLC) patient samples/cell lines and STAT3 inhibition in NSCLC cell lines markedly impairs their survival. STAT3 also plays a pivotal role in driving tumor-promoting inflammation and evasion of anti-tumor immunity. Consequently, targeting STAT3 either directly or by inhibition of upstream regulators such as Interleukin-6 (IL-6) or Janus kinase 1/2 (JAK1/2) is considered as a promising treatment strategy for the management of NSCLC. In contrast, some studies also report STAT3 being a tumor suppressor in a variety of solid malignancies, including lung cancer. Here, we provide a concise overview of STAT3‘s versatile roles in NSCLC and discuss the yins and yangs of STAT3 targeting therapies.

Trichomicin Suppresses Colorectal Cancer via Comprehensive Regulation of IL-6 and TNFα in Tumor Cells, TAMs, and CAFs

Trichomicin, a small-molecule compound isolated from fungi, has been identified with bioactivity of antitumor. In this study, a colon cancer subcutaneous mice model was used to evaluate the antitumor effects of Trichomicin in vivo. Treatment with Trichomicin significantly inhibited tumor growth in a xenograft mouse colon cancer model. The underlying molecular mechanism has also been investigated through the quantification of relevant proteins. The expression levels of IL-6 and TNFα were reduced in tumor tissues of mice treated with Trichomicin, which was consistent with results of in vitro experiments in which Trichomicin suppressed the expression of IL-6 and TNFα in tumor and stromal cells. In addition, Trichomicin inhibited TNFα-induced activation of NF-κB and basal Stat3 signaling in vitro, which resulted in reduced expression of the immune checkpoint protein PD-L1 in tumor and stromal cells. Conclusively, Trichomicin, a promising new drug candidate with antitumor activity, exerted antitumor effects against colon cancer through inhibition of the IL-6 and TNFα signaling pathways.

STAT1 as a potential prognosis marker for poor outcomes of early stage colorectal cancer with microsatellite instability

Proteomic analyses indicate that STAT1 protein (signal transducer and activator of transcription 1 or transcription factor ISGF-3 components p91/p84) is upregulated in some colorectal cancers. This study examined 736 colorectal cancer patients for the expression of STAT1 protein in tissue specimens, including 614 early stage patients and 122 advanced stage patients. Tissue microarrays were constructed, and STAT1 expression was examined by immunohistochemistry and scored semi-quantitatively. Among all cases, 9% of cases displayed high levels of cytoplasmic expression of STAT1 and 15% of cases had positive nuclear expression. Based on statistical analyses of a cohort of 559 early stage patients with survival data and no neoadjuvant therapy, we found that high levels of cytoplasmic expression of STAT1 correlated with shorter survival time in early stage colorectal cancer, particularly of the microsatellite instability (MSI) subtype. Additional analysis of a 244-case cohort of colorectal cancers from the Cancer Genome Atlas found that STAT1 gene expression correlated positively with PD-L1 (CD274) and PD-1 (PDCD1) but had no correlation with KRAS or BRAF mutation status. STAT1 expression showed no clear correlation with any of the 4 clinical diagnostic markers of mismatch repair, MLH1, MSH2, MSH6, and PMS2, suggesting its potential as an independent outcome marker for MSI cancers. Our findings suggest that STAT1 may be used as a potential prognostic protein marker for stratifying the outcome risk of early stage MSI colorectal cancer.

FKBP14 Promotes The Proliferation And Migration Of Colon Carcinoma Cells Through Targeting IL-6/STAT3 Signaling Pathway

PURPOSE

FK506-binding proteins 14 (FKBP14), a highly conserved protein, is identified as an oncogene in certain human tumors. However, the detailed biological function of FKBP14 in colon carcinoma remains unclear. The purpose of the present research is to examine the role of FKBP14 in human colon carcinoma cells.

METHODS

In the present study, FKBP14 induced silencing and overexpression in colon carcinoma cells by using RNA interference (RNAi) and lentiviral vector, respectively. A specific JAK/STAT inhibitor AG490 was used to explore the relationship between FKBP14 and STAT3 in colon carcinoma cells. Moreover, quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to examine the level of FKBP14 in colon carcinoma cells. Cell counting kit-8 (CCK-8) assay was used to determine the proliferation rate of colon carcinoma cells. Further, the migration rate of colon carcinoma cells was analyzed by performing a migration assay.

RESULTS

Our results demonstrated that FKBP14 was upregulated in human colon carcinoma tissues. Moreover, high level of FKBP14 was associated with poor prognosis of colon carcinoma patients. Further, our findings firstly elucidated that FKBP14 was a pro-proliferation and migration factor in colon carcinoma cells. More importantly, FKBP14 might be a novel component in IL-6/JAK/STAT3 pathway and targeted STAT3 in colon carcinoma cells.

CONCLUSION

Our research not only indicated the potential signaling pathway of FKBP14 in colon carcinoma cells but also provided novel insight into the treatment for colon carcinoma.

STAT3 and STAT5 Activation in Solid Cancers

The Signal Transducer and Activator of Transcription (STAT)3 and 5 proteins are activated by many cytokine receptors to regulate specific gene expression and mitochondrial functions. Their role in cancer is largely context-dependent as they can both act as oncogenes and tumor suppressors. We review here the role of STAT3/5 activation in solid cancers and summarize their association with survival in cancer patients. The molecular mechanisms that underpin the oncogenic activity of STAT3/5 signaling include the regulation of genes that control cell cycle and cell death. However, recent advances also highlight the critical role of STAT3/5 target genes mediating inflammation and stemness. In addition, STAT3 mitochondrial functions are required for transformation. On the other hand, several tumor suppressor pathways act on or are activated by STAT3/5 signaling, including tyrosine phosphatases, the sumo ligase Protein Inhibitor of Activated STAT3 (PIAS3), the E3 ubiquitin ligase TATA Element Modulatory Factor/Androgen Receptor-Coactivator of 160 kDa (TMF/ARA160), the miRNAs miR-124 and miR-1181, the Protein of alternative reading frame 19 (p19ARF)/p53 pathway and the Suppressor of Cytokine Signaling 1 and 3 (SOCS1/3) proteins. Cancer mutations and epigenetic alterations may alter the balance between pro-oncogenic and tumor suppressor activities associated with STAT3/5 signaling, explaining their context-dependent association with tumor progression both in human cancers and animal models.

Long noncoding RNA HAS2-AS1 promotes tumor progression in glioblastoma via functioning as a competing endogenous RNA

Glioblastoma multiforme (GBM) is a refractory tumor with poor prognosis and requires more effective treatment regimens. It has been confirmed that long noncoding RNAs (lncRNAs) substantially regulate various human disease including GBM. However, the biological roles and its underlying molecular mechanisms still need to be further investigated. In this study, the biological function and potential molecular mechanism of lncHAS2-AS1 in GBM were explored. It was discovered that HAS2-AS1 was elevated in glioma tissues and correlated with the prognosis of patients with glioma. Reduction of HAS2-AS1 suppressed the migration and invasion in vitro and in vivo. The transcription factor STAT1 could raise HAS2-AS1 by binding to its promoter region. Besides, HAS2-AS1 could adjust PRPS1 via sponging miR-608 in a direct manner. On the whole, the results of this study evidence that HAS2-AS1 is an oncogene and a potential therapeutic target for GBM.

Analysis of the promoter region of the human miR-32 gene in colorectal cancer

The pathogenesis of colorectal cancer (CRC) is poorly understood. MicroRNA (miR)-32 upregulation in CRC tissues was previously reported, where it increased the proliferation, migration and invasion, and reduced apoptosis of CRC cells by inhibiting the expression of phosphatase and tensin homolog (PTEN). However, the mechanism underlying miR-32 upregulation remains unknown. miR-32 is an intronic miRNA located within intron 14 of the transmembrane protein 245 gene (TMEM245). The present study aimed to elucidate the biological pathways underlying miR-32 regulation in CRC. A truncated promoter containing the 5′-flanking region of TMEM245/miR-32 gene was constructed. The promoter region was analyzed by dual luciferase reporter assay in CRC cells. DNA pull-down assay and mass spectrometry (MS) were used to identify proteins binding to the core promoter. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and transcription factor (TF) analyses were used to identify the binding proteins. The −320 to −1 bp fragment of the 5′-flanking region exhibited the highest luciferase activity. The regions spanning −606 to −320 bp exhibited a significant decrease in luciferase activity, compared with the −320 to −1 bp fragment. DNA pull-down assay and MS revealed 403 potential miR-32 promoter binding proteins. GO and KEGG pathway analysis indicated that these proteins were involved in numerous physiological and biochemical processes, including ‘structural molecule activity’, ‘RNA binding’, ‘small molecule metabolic process’ and ‘biogenesis’. Furthermore, TF analysis revealed 10 potential interacting TFs, including SMAD family member 1 (SMAD1), signal transducer and activator of transcription 1 (STAT1) and forkhead box K1 (Foxk1). These results suggested that the core promoter region may be located within-320 to −1 bp of the 5′-flanking region of TMEM245/miR-32 gene, while the region from −606 to −320 bp may harbor repressive regulatory elements. The TFs SMAD1, STAT1 and Foxk1 may be involved in the transcriptional regulation of miR-32.

The intricate role of miR-155 in carcinogenesis: potential implications for esophageal cancer research

MiRNAs have immerged as essential modulators of key cellular procuresses involved in post-transcriptional regulation of the human transcriptome. They are essential components of complex regulatory networks that modulate most important physiological functions of cells. MicroRNA-155 (miR-155) is a multifaceted regulator of cell proliferation, cell cycle, development, immunity and inflammation that plays pivotal, and sometimes contradictory, roles in numerous cancers including esophageal cancer. Here, we review the intricate role of miR-155 in cancer by exemplifying carcinogenesis of various tumors, focusing on recent findings that may provide a link between miR-155 and esophageal cancer-related pathways.

Dichotomal functions of phosphorylated and unphosphorylated STAT1 in hepatocellular carcinoma

Abstract

Interferons (IFNs) with antiviral and immune-stimulatory functions have been widely used in prevention and treatment of hepatocellular carcinoma (HCC). Signal transducer and activator of transcription 1 (STAT1) is a key element of the IFN signaling, and the function of STAT1 is critically determined by its phosphorylation state. This study aims to understand the functions of phosphorylated (p-) and unphosphorylated (u-) STAT1 in HCC. We found that u-STAT1 is significantly elevated in patient HCC tumor tissues and predominantly expressed in cytoplasm; while p-STAT1 is absent. Loss of u-STAT1 potently arrested cell cycle and inhibited cell growth in HCC cells. Induction of p-STAT1 by IFN-α treatment effectively triggers the expression of interferon-stimulated genes (ISGs), but has moderate effect on HCC cell growth. Interestingly, both u-STAT1 and p-STAT1 are induced by IFN-α, through with distinct time-dependent process. Furthermore, the ISG induction patterns mediated by p-STAT1 and u-STAT1 are also distinct. Importantly, artificial blocking of the induction of u-STAT1, but not p-STAT1, sensitizes HCC cells to treatment of IFNs. Therefore, p-STAT1 and u-STAT1 exert dichotomal functions and coordinately regulate the responsiveness to IFN treatment in HCC.

Key Messages

STAT1 is upregulated and predominantly presented as u-STAT1 in HCC, while p-STAT1 is absent.

U-STAT1 sustains but p-STAT1 inhibits HCC growth.

The dynamic change of phosphorylation state of STAT1 control the responsiveness to IFN treatment.

Electronic supplementary material

The online version of this article (10.1007/s00109-018-1717-7) contains supplementary material, which is available to authorized users.