Expression of epithelial-mesenchymal transition and cancer stem cell markers in colorectal adenocarcinoma: Clinicopathological significance

Association between the expression of epithelial-mesenchymal transition (EMT)-related markers and oncologic outcomes of colorectal cancer

BACKGROUND

Epithelial-mesenchymal transition (EMT) is a key step in the development of colorectal cancer (CRC) that confers metastatic capabilities to cancer cells. The present study aimed to assess the immunohistochemical (IHC) expression and impact of EMT markers, including E-cadherin, Vimentin, β-catenin, and SMAD4, on the oncologic outcomes of CRC.

METHODS

This was a retrospective review of 118 CRC patients. Tissue slides were retrieved from the slide archive and five tissue microarray construction blocks were constructed. IHC for E-cadherin, Vimentin, β-catenin, and SMAD4 was done. The main outcome was the association between abnormal marker expression and overall survival (OS), and disease-free survival (DFS).

RESULTS

Adenocarcinomas accounted for 71.2% of tumors, whereas 25.4% and 3.4% were mucinous and signet ring cell carcinomas. The rates of lymphovascular invasion and perineural invasion were 72.9% and 20.3%, respectively. There was a positive, significant correlation, and association between the four markers. Abnormal expression of E-cadherin was associated with significantly lower OS (p < 0.0001) and similar DFS (p = 0.06). Abnormal Vimentin expression was associated with a significantly higher rate of distant metastasis (p = 0.005) and significantly lower OS and DFS (p < 0.0001). Abnormal expression of β-catenin was associated with significantly lower OS (p < 0.0001) and similar DFS (p = 0.15). Abnormal expression of SMAD4 was associated with significantly lower OS and DFS (p < 0.0001). Abnormal expression of all four markers was associated with a higher disease recurrence, lower OS, and lower DFS.

CONCLUSION

Abnormal expression of each marker was associated with lower OS, whereas abnormal expression of Vimentin and SMAD4 only was associated with lower DFS.

Racial disparities in colorectal cancer clinicopathological and molecular tumor characteristics: a systematic review

PURPOSE

African Americans have the highest colorectal cancer (CRC) mortality of all racial groups in the USA, which may relate to differences in healthcare access or advanced stage at diagnosis. Recent evidence indicates that differences in tumor characteristics may also underlie disparities in mortality. To highlight recent findings and areas for investigation, we completed the first systematic review of racial disparities in CRC tumor prognostic markers, including clinicopathological markers, microsatellite instability (MSI), oncogene mutations, and novel markers, including cancer stem cells and immune markers.

METHODS

Relevant studies were identified via PubMed, limited to original research published within the last 10 years. Ninety-six articles were identified that compared the prevalence of mortality-related CRC tumor characteristics in African Americans (or other African ancestry populations) to White cases.

RESULTS

Tumors from African ancestry cases are approximately 10% more likely to contain mutations in KRAS, which confer elevated mortality and resistance to epidermal growth factor receptor inhibition. Conversely, African Americans have approximately 50% lower odds for BRAF-mutant tumors, which occur less frequently but have similar effects on mortality and therapeutic resistance. There is less consistent evidence supporting disparities in mutations for other oncogenes, including PIK3CA, TP53, APC, NRAS, HER2, and PTEN, although higher rates of PIK3CA mutations and lower prevalence of MSI status for African ancestry cases are supported by recent evidence. Although emerging evidence suggests that immune markers reflecting anti-tumor immunity in the tumor microenvironment may be lower for African American cases, there is insufficient evidence to evaluate disparities in other novel markers, cancer stem cells, microRNAs, and the consensus molecular subtypes.

CONCLUSION

Higher rates of KRAS-mutant tumors in in African Americans may contribute to disparities in CRC mortality. Additional work is required to understand whether emerging markers, including immune cells, underlie the elevated CRC mortality observed for African Americans.

Association Between the Immunohistochemistry Expression of E-cadherin, Beta-Catenin, and CD44 in Colorectal Adenocarcinoma

Background Colorectal cancer is a leading cause of cancer-related deaths worldwide, and epithelial-mesenchymal transition (EMT) plays an important role in cancer metastasis. In EMT, there is downregulation of E-cadherin, an intracellular adhesion molecule, as well as mutations in beta-catenin genes. On immunohistochemistry (IHC), the expression of CD44 portrays stem cell differentiation, which, in turn, is strongly associated with EMT. Thus, newer targeted therapies can be advised based on the expression of EMT and stem cell differentiation. Aims and objectives To determine the IHC expression of E-cadherin, beta-catenin, and CD44 in colorectal adenocarcinoma and find the association of the IHC expression of E-cadherin, beta-catenin, and CD44 with the histopathological grade, stage, lymph node metastasis, and lymphovascular invasion of colorectal adenocarcinoma. Materials and methods Fifty histologically proven cases of colorectal adenocarcinoma from 2016 to 2021 were included in this study, and clinicopathological data including age, gender, grading, TNM (tumour, node, and metastasis) staging, and lymph node metastasis were collected and hematoxylin and eosin slides were reviewed. IHC staining for E-cadherin, beta-catenin, and CD44 was done for all cases using the peroxidase and anti-peroxidase method, and the results were analysed. Results Peak incidence occurred in the 61-70 years age group (36%), and the most common site of the tumour was the rectal area (48%). The majority of the cases were in TNM stage II (37.3%), and a low expression of E-cadherin was found to be associated with higher T stage (p = 0.03), TNM staging (p = 0.04), as well as the presence of lymph node metastasis (p = 0.006). High beta-catenin expression was observed to have a significant correlation with a higher T stage (p = 0.006) and TNM staging (p = 0.005), while high CD44 expression was found to be associated with lymph node metastasis (p = 0.01). Altered expression of EMT-related proteins (E-cadherin and beta-catenin) showed a significant correlation with higher T stage (p = 0.03), TNM staging (p = 0.016), and lymph node metastasis (0.04). Conclusions EMT and cancer stem cell IHC markers are biomarkers for aggressive tumour growth and lymph node metastasis. Hence, EMT markers (E-cadherin and beta-catenin) and cancer stem cell markers (CD44) can be used as prognostic markers.

The complex network of transcription factors, immune checkpoint inhibitors and stemness features in colorectal cancer: A recent update

Cancer immunity is regulated by several mechanisms that include co-stimulatory and/or co-inhibitory molecules known as immune checkpoints expressed by the immune cells. In colorectal cancer (CRC), CTLA-4, LAG3, TIM-3 and PD-1 are the major co-inhibitory checkpoints involved in tumor development and progression. On the other hand, the deregulation of transcription factors and cancer stem cells activity plays a major role in the development of drug resistance and in the spread of metastatic disease in CRC. In this review, we describe how the modulation of such transcription factors affects the response of CRC to therapies. We also focus on the role of cancer stem cells in tumor metastasis and chemoresistance and discuss both preclinical and clinical approaches for targeting stem cells to prevent their tumorigenic effect. Finally, we provide an update on the clinical applications of immune checkpoint inhibitors in CRC and discuss the regulatory effects of transcription factors on the expression of the immune inhibitory checkpoints with specific focus on the PD-1 and PD-L1 molecules.

Cancer Metastasis and Treatment Resistance: Mechanistic Insights and Therapeutic Targeting of Cancer Stem Cells and the Tumor Microenvironment

Cancer metastasis and treatment resistance are the main causes of treatment failure and cancer-related deaths. Their underlying mechanisms remain to be fully elucidated and have been attributed to the presence of cancer stem cells (CSCs)-a small population of highly tumorigenic cancer cells with pluripotency and self-renewal properties, at the apex of a cellular hierarchy. CSCs drive metastasis and treatment resistance and are sustained by a dynamic tumor microenvironment (TME). Numerous pathways mediate communication between CSCs and/or the surrounding TME. These include a paracrine renin-angiotensin system and its convergent signaling pathways, the immune system, and other signaling pathways including the Notch, Wnt/β-catenin, and Sonic Hedgehog pathways. Appreciation of the mechanisms underlying metastasis and treatment resistance, and the pathways that regulate CSCs and the TME, is essential for developing a durable treatment for cancer. Pre-clinical and clinical studies exploring single-point modulation of the pathways regulating CSCs and the surrounding TME, have yielded partial and sometimes negative results. This may be explained by the presence of uninhibited alternative signaling pathways. An effective treatment of cancer may require a multi-target strategy with multi-step inhibition of signaling pathways that regulate CSCs and the TME, in lieu of the long-standing pursuit of a 'silver-bullet' single-target approach.

Hepcidin Upregulation in Colorectal Cancer Associates with Accumulation of Regulatory Macrophages and Epithelial-Mesenchymal Transition and Correlates with Progression of the Disease

Advanced, metastatic colorectal cancer (CRC) is associated with high rate of mortality because of its poor responsiveness to chemotherapy/immunotherapy. Recent studies have shown that hepcidin, a peptide hormone produced mainly by hepatocytes, is expressed by and enhances the growth of tumor cells. We here assessed whether hepcidin expression helps identify subsets of CRC with advanced and aggressive course. By integrating results of in vitro/ex vivo studies with data of bioinformatics databases, we initially showed that hepcidin RNA and protein expression was more pronounced in tissue samples taken from the tumor area, as compared to the macroscopically unaffected, adjacent, colonic mucosa of CRC patients. The induction of hepcidin in the colonic epithelial cell line HCEC-1ct by interleukin (IL)-6, IL-21 and IL-23 occurred via a Stat3-dependent mechanism and, in primary CRC cells, hepcidin co-localized with active Stat3. In CRC tissue, hepcidin content correlated mainly with macrophage accumulation and IL-10 and CD206 expression, two markers of regulatory macrophages. Consistently, both IL-10 and CD206 were up-regulated by hepcidin in blood mononuclear cells. The highest levels of hepcidin were found in metastatic CRC and survival analysis showed that high expression of hepcidin associated with poor prognosis. Moreover, hepcidin expression correlated with markers of epithelial-to-mesenchymal transition and the silencing of hepcidin in CRC cells reduced epithelial-to-mesenchymal transition markers. These findings indicate that hepcidin is markedly induced in the advanced stages of CRC and suggest that it could serve as a prognostic biomarker in CRC.

Autophagy: A Versatile Player in the Progression of Colorectal Cancer and Drug Resistance

Colorectal cancer (CRC) is among the topmost malignancies for both genders. Despite the high incidence rate and advances in diagnostic tools, treatment in many cases is still ineffective. Most cancerous lesions in CRC begin as benign, followed by the development of invasive forms and metastases. The development of CRC has been linked to defects in autophagy, which plays both a pro-and anti-tumor role and is mainly context-dependent. Autophagy suppression could enhance apoptosis via p53 activation, or autophagy also promotes tumor progression by maintaining tumor growth and increasing resistance to chemotherapy. Autophagy promotes the invasion and metastasis of CRC cells via increased epithelial-mesenchymal transition (EMT). Moreover, dysbiosis of gut microbiota upregulated autophagy and metastasis markers. Autophagy responses may also modulate the tumor microenvironment (TME) via regulating the differentiation process of several innate immune cells. Treatments that promote tumor cell death by stimulating or inhibiting autophagy could be beneficial if used as an adjunct treatment, but the precise role of various autophagy-modulating drugs in CRC patients is needed to be explored. In this article, we present an overview of the autophagy process and its role in the pathogenesis and therapeutic resistance of CRC. Also, we focused on the current understanding of the role of the EMT and TME, including its relation to gut microbiota and immune cells, in autophagic manipulation of CRC. We believe that there is a potential link between autophagy, TME, EMT, and drug resistance, suggesting that further studies are needed to explore this aspect.

Identification of a Four-Gene-Based SERM Signature for Prognostic and Drug Sensitivity Prediction in Gastric Cancer

Background

Gastric cancer (GC) is a highly molecular heterogeneous tumor with poor prognosis. Epithelial-mesenchymal transition (EMT) process and cancer stem cells (CSCs) are reported to share common signaling pathways and cause poor prognosis in GC. Considering about the close relationship between these two processes, we aimed to establish a gene signature based on both processes to achieve better prognostic prediction in GC.

Methods

The gene signature was constructed by univariate Cox and the least absolute shrinkage and selection operator (LASSO) Cox regression analyses by using The Cancer Genome Atlas (TCGA) GC cohort. We performed enrichment analyses to explore the potential mechanisms of the gene signature. Kaplan-Meier analysis and time-dependent receiver operating characteristic (ROC) curves were implemented to assess its prognostic value in TCGA cohort. The prognostic value of gene signature on overall survival (OS), disease-free survival (DFS), and drug sensitivity was validated in different cohorts. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) validation of the prognostic value of gene signature for OS and DFS prediction was performed in the Fudan cohort.

Results

A prognostic signature including SERPINE1, EDIL3, RGS4, and MATN3 (SERM signature) was constructed to predict OS, DFS, and drug sensitivity in GC. Enrichment analyses illustrated that the gene signature has tight connection with the CSC and EMT processes in GC. Patients were divided into two groups based on the risk score obtained from the formula. The Kaplan-Meier analyses indicated high-risk group yielded significantly poor prognosis compared with low-risk group. Pearson’s correlation analysis indicated that the risk score was positively correlated with carboplatin and 5-fluorouracil IC50 of GC cell lines. Multivariate Cox regression analyses showed that the gene signature was an independent prognostic factor for predicting GC patients’ OS, DFS, and susceptibility to adjuvant chemotherapy.

Conclusions

Our SERM prognostic signature is of great value for OS, DFS, and drug sensitivity prediction in GC, which may give guidance to the development of targeted therapy for CSC- and EMT-related gene in the future.

Molecular subclassification of gastrointestinal cancers based on cancer stem cell traits

Human gastrointestinal malignancies are highly heterogeneous cancers. Clinically, heterogeneity largely contributes to tumor progression and resistance to therapy. Heterogeneity within gastrointestinal cancers is defined by molecular subtypes in genomic and transcriptomic analyses. Cancer stem cells (CSCs) have been demonstrated to be a major source of tumor heterogeneity; therefore, assessing tumor heterogeneity by CSC trait-guided classification of gastrointestinal cancers is essential for the development of effective therapies. CSCs share critical features with embryonic stem cells (ESCs). Molecular investigations have revealed that embryonic genes and developmental signaling pathways regulating the properties of ESCs or cell lineage differentiation are abnormally active and might be oncofetal drivers in certain tumor subtypes. Currently, multiple strategies allow comprehensive identification of tumor subtype-specific oncofetal signatures and evaluation of subtype-specific therapies. In this review, we summarize current knowledge concerning the molecular classification of gastrointestinal malignancies based on CSC features and elucidate their clinical relevance. We also outline strategies for molecular subtype identification and subtype-based therapies. Finally, we explore how clinical implementation of tumor classification by CSC subtype might facilitate the development of more effective personalized therapies for gastrointestinal cancers.

Novel therapeutic strategies: targeting epithelial-mesenchymal transition in colorectal cancer

Epithelial-mesenchymal transition (EMT) is a process during which cells lose their epithelial characteristics, for instance apical-basal cell polarity and cell-cell contact, and gain mesenchymal properties, such as increased motility. In colorectal cancer, EMT has an important role in tumour progression, metastasis, and drug resistance. There has been accumulating evidence from preclinical and early clinical studies that show that EMT markers might serve as outcome predictors and potential therapeutic targets in colorectal cancer. This Review describes the fundamentals of EMT, including biology, newly partial EMT, and associated changes. We also provide a comprehensive summary of therapeutic compounds capable of targeting EMT markers, including drugs in preclinical and clinical trials and those with repurpose potential. Lastly, we explore the obstacles of EMT bench-to-bedside drug development.

Cancer stem cells in colorectal cancer and the association with chemotherapy resistance

The incidence and mortality of colorectal cancer (CRC) have always been among the highest in the world, although the diagnosis and treatment are becoming more and more advanced. At present, the main reason is that patients have acquired drug resistance after long-term conventional drug treatment. An increasing number of evidences confirm the existence of cancer stem cells (CSCs), which are a group of special cells in cancer, only a small part of cancer cells. These special cell populations are not eliminated by chemotherapeutic drugs and result in tumor recurrence and metastasis after drug treatment. CSCs have the ability of self-renewal and multidirectional differentiation, which is associated with the occurrence and development of cancer. CSCs can be screened and identified by related surface markers. In this paper, the characteristic surface markers of CSCs in CRC and the related mechanism of drug resistance will be discussed in detail. A better understanding of the mechanism of CSCs resistance to chemotherapy may lead to better targeted therapy.

Snail-Family Proteins: Role in Carcinogenesis and Prospects for Antitumor Therapy

The review analyzes Snail family proteins, which are transcription factors involved in the regulation of the epithelial-mesenchymal transition (EMT) of tumor cells. We describe the structure of these proteins, their post-translational modification, and the mechanisms of Snail-dependent regulation of genes. The role of Snail proteins in carcinogenesis, invasion, and metastasis is analyzed. Furthermore, we focus on EMT signaling mechanisms involving Snail proteins. Next, we dissect Snail signaling in hypoxia, a condition that complicates anticancer treatment. Finally, we offer classes of chemical compounds capable of down-regulating the transcriptional activity of Snails. Given the important role of Snail proteins in cancer biology and the potential for pharmacological inhibition, Snail family proteins may be considered promising as therapeutic targets.

EMT, cancer stem cells and autophagy; The three main axes of metastasis

Epithelial-mesenchymal transition (EMT) and Cancer stem-like cells (CSCs) are major factors contributing to the metastasis of cancer cells. Consequently, the signaling pathways involved in both processes are appropriate therapeutic targets in the treatment of metastasis. Autophagy is another process that has recently attracted the attention of many researchers; depending on the type of cancer and tissue and the stage of cancer, this process can play a dual role in the development of cancer cells. Studies on cancer cells have shown that different signaling pathways are involved in all three processes, namely, cancer stem cells, autophagy, and EMT. The purpose of this study was to investigate and elucidate the relationship between the effective signaling pathways in all three processes, which could play an effective role in determining appropriate therapeutic goals.

Prognostic impact of tumor budding and EMT in periampullary adenocarcinoma: a quantitative approach

The presence of invasive cell clusters known as tumor budding and the closely related epithelial mesenchymal transition (EMT) have a prognostic impact on cancer patients' overall survival. Interestingly, data quantitatively analyzing and correlating the amount of tumor buds and patient overall survival as well as the impact of expression of epithelial phenotype markers are missing. Periampullary carcinoma samples of 171 patients were immunohistochemically stained for E-Cadherin (ECad). Tumor cell clusters (TCC, defined from one to 50 cells) were manually quantified comprising tumor cell number and subcellular localization of ECad expression (membranous, cytoplasmic or mixed). Data analyses were performed using elastic net feature selection. Hereby, five distinct intervals of TCC sizes and corresponding fractions of cells with distinct ECad expression were identified. Prognostic features of the defined budding categories were entered into a subsequent Cox regression model together with standard clinicopathological parameters and, based on the model prediction, cases were categorized into "low and high budding" grades. Overall median TCC size was 16 cells (range: 2-36 cells). The median number of TCCs per tumor was 42 (range: 3-283). Elastic net feature selection identified TCCs of 6-10 and 31-35 cells as prognostically most relevant negative and positive features, respectively. Regarding ECad expression, cytoplasmic ECad expression in TCCs of 11-15 as well as of 26-30 cells revealed prognostic relevance. Combining TCC numbers and ECad expression, budding grade qualified as independent prognostic factor for patient overall survival (p<0.001) in a multivariable clinicopathologic Cox model. Applying an advanced modelling by machine learning on a cohort of periampullary cancers, we show that not the smallest TCCs (1-5 cells) but tumor cell nests containing 6-10 cells display the strongest negative prognostic relevance. Moreover, we demonstrate that larger TCCs might have a strong positive prognostic impact in periampullary adenocarcinomas, contributing to establishing an advanced grading system.

Slow-Cycling Cancer Stem Cells Regulate Progression and Chemoresistance in Colon Cancer

Cancer chemoresistance is often attributed to the presence of cancer stem cell (CSC)-like cells, but whether they are homogeneously chemoresistant remains unclear. We previously showed that in colon tumors, a subpopulation of LGR5⁺ CSC-like cells driven by TCF1 (TCF7), a Wnt-responsive transcription factor, were responsible for tumorigenicity. Here we demonstrate that the tumorigenic subpopulation of mouse LGR5⁺ cells exists in a slow-cycling state and identify a unique 22-gene signature that characterizes these slow-cycling CSC. Seven of the signature genes are specifically expressed in slow-cycling LGR5⁺ cells from xenografted human colon tumors and are upregulated in colon cancer clinical specimens. Among these seven, four genes (APCDD1, NOTUM, PROX1, and SP5) are known to be direct Wnt target genes, and PROX1 was expressed in the invasive fronts of colon tumors. PROX1 was activated by TCF1 to induce CDKN1C and maintain a slow-cycling state in colon cancer organoids. Strikingly, PROX1 was required for recurrent growth after chemotherapeutic treatment, suggesting that inhibition of slow-cycling CSC by targeting the TCF1-PROX1-CDKN1C pathway is an effective strategy to combat refractory colon cancer in combination with conventional chemotherapy. SIGNIFICANCE: These findings illustrate the importance of a slow-cycling CSC subpopulation in colon cancer development and chemoresistance, with potential implications for the identified slow-cycling CSC signatures and the TCF1-PROX1-CDKN1C pathway as therapeutic targets.

Correlation of clinicopathological features and LGR5 expression in colon adenocarcinoma

Colon cancer stem cells (CSCs) are closely related to tumorigenesis and treatment response, and LGR5 is currently the most robust and reliable CSC marker in colorectal cancer (CRC). However, LGR5 expression in CRC tumor budding (TB) is not well understood. We examined the clinicopathological and prognostic significance of LGR5 in CRC TB. LGR5 expression was evaluated by RNAscope, a newly developed RNA in situ hybridization technique, using a tissue microarray consisting of 55 patient samples of TB in colon adenocarcinoma (CA) selected from the medical archives at our hospital. Patients were stratified into negative and positive LGR5 expression groups. Tumor-infiltrating lymphocytes (TILs) and histological grade were lower in the LGR5-positive group compared with the LGR5-negative group (P = .0407 and P = .0436, respectively). There was no significant difference in overall survival between the LGR5-positive group and the LGR5-negative group (log-rank test, P = .6931). LGR5 expression did not remain a predictor of prognosis in univariate analysis (OR = 0.84, 95% CI: 0.33-2.02, P = .6928). LGR5 expression may be affected by TILs, which have been demonstrated to be associated with worse prognosis in the budding area of CA and is an important potential marker of prognosis.

Cadherins down-regulation: towards a better understanding of their relevance in colorectal cancer

The down-regulation of cadherin expression in colorectal cancer (CRC) has been widely studied. However, existing data on cadherin expression are highly variable and its relevance to CRC development has not been completely established. This review examines published studies on cadherins whose down-regulation has been already demonstrated in CRC, trying to establish a relationship with promoter methylation, the capacity to influence the Wnt / CTNNB1 (catenin beta 1, beta-catenin) signalling pathway and the clinical implications for disease outcome. Moreover, it also analyses factors that may explain data variability and highlights the importance of considering the altered subcellular localization of the examined cadherins. The results of this survey reveal that thirty of one hundred existing cadherins appear to be down-regulated in CRC. Among these, ten are cadherins, sixteen are protocadherins, equally divided between clustered and non clustered, and four are cadherin - related. These findings suggest that, to better define the role played by cadherin down-regulation in CRC pathogenesis, the expression of multiple rather than individual cadherins should be taken into account and further functional studies are necessary to clarify the relative ability of individual cadherins to inhibit CTNNB1 therefore acting as tumor suppressors.

The Association Between Inflammation, Epithelial Mesenchymal Transition and Stemness in Colorectal Carcinoma

Background

Inflammation plays an important albeit dual role in carcinogenesis. Survival studies have highlighted the prognostic significance of peritumorous inflammation. Currently, the theoretical background allows inflammation, epithelial mesenchymal transition (EMT) and the closely associated stem cell differentiation in colorectal carcinoma (CRC) to be linked. However, there is scarce direct morphological evidence.

Purpose and methods

The aim of our study was to investigate the role of inflammation in cancer growth and invasion by analyzing the association between inflammation and known morphological prognostic features of colorectal cancer, EMT, stemness and mismatch repair (MMR) protein expression. The study was designed as a retrospective morphological and immunohistochemical assessment of 553 consecutive cases of surgically treated primary CRC.

Results

There were statistically significant associations between high-grade inflammation and lower pT (p = 0.002), absence of lymph node metastases (p < 0.001) and less frequent lymphatic (p = 0.003), venous (p = 0.017), arterial (p = 0.012), perineural (p = 0.001) and intraneural (p = 0.01) invasion. In contrast, Crohn's like reaction (CLR) by density of lymphoid follicles in the invasive front lacked significant differences in regard to pT, pN, tumor invasion into surrounding structures (blood or lymphatic vessels, nerves), grade or necrosis (all p > 0.05). The expression of E-cadherin, CD44 and MMR proteins yielded no statistically significant associations with peritumorous inflammation by Klintrup-Mäkinen score or the density of lymphoid follicles. Nevertheless, E-cadherin levels were significantly associated with the density of eosinophils (p = 0.007).

Conclusion

High-grade peritumorous inflammation is associated with beneficial morphologic CRC features, including less frequent manifestations of invasion, and is not secondary to tissue damage and necrosis. CLR is not associated with cancer spread by pTN; this finding indirectly suggests an independent role of CLR in carcinogenesis. Further, inflammation by Klintrup-Mäkinen grade and CLR is not dependent on epithelial-mesenchymal transition and stem cell differentiation. Our study highlights the complex associations between inflammation, tumor morphology, EMT, stemness and MMR protein expression in human CRC tissues.

DCLK1 Monoclonal Antibody-Based CAR-T Cells as a Novel Treatment Strategy against Human Colorectal Cancers

CAR-T (chimeric antigen receptor T cells) immunotherapy is effective in many hematological cancers; however, efficacy in solid tumors is disappointing. Doublecortin-like kinase 1 (DCLK1) labels tumor stem cells (TSCs) in genetic mouse models of colorectal cancer (CRC). Here, we describe a novel CAR-T targeting DCLK1 (CBT-511; with our proprietary DCLK1 single-chain antibody variable fragment) as a treatment strategy to eradicate CRC TSCs. The cell surface expression of DCLK1 and cytotoxicity of CBT-511 were assessed in CRC cells (HT29, HCT116, and LoVo). LoVo-derived tumor xenografts in NOD Scid gamma (NSG^TM)mice were treated with CBT-511 or mock CAR-T cells. Adherent CRC cells express surface DCLK1 (two-dimensional, 2D). A 4.5-fold increase in surface DCLK1 was observed when HT29 cells were grown as spheroids (three-dimensional, 3D). CBT-511 induced cytotoxicity (2D; p < 0.0001), and increased Interferon gamma (IFN-γ) release in CRC cells (2D) compared to mock CAR-T (p < 0.0001). Moreover, an even greater increase in IFN-γ release was observed when cells were grown in 3D. CBT-511 reduced tumor growth by approximately 50 percent compared to mock CAR-T. These data suggest that CRC cells with increased clonogenic capacity express increased surface DCLK1. A DCLK1-targeted CAR-T can induce cytotoxicity in vitro and inhibit xenograft growth in vivo.

STIP1 Regulates Proliferation and Migration of Lung Adenocarcinoma Through JAK2/STAT3 Signaling Pathway

Purpose

Recent studies have shown that STIP1 is associated with proliferation and migration in numerous types of tumors; however, the role of STIP1 in lung adenocarcinoma is still poorly understood. Therefore, the aim of this study was to evaluate the role of STIP1 in lung adenocarcinoma, in vitro and in vivo.

Methods

The expression of STIP1 in lung adenocarcinoma was assessed by immunohistochemistry, RT-qPCR, and Western blot. The effects of STIP1 on the proliferation of lung adenocarcinoma cells were detected by the cell counting kit-8 assay; the effect of STIP1 on adhesion of lung adenocarcinoma cells was detected by Giemsa staining, while the cell scratch and Transwell assays were employed to examine the effect of STIP1 on the migratory ability of lung adenocarcinoma cells. Finally, apoptosis was evaluated by Hoechst staining and flow cytometry.

Results

The expression level of STIP1 in lung adenocarcinoma tissue was significantly higher than that in adjacent normal tissue (P<0.05). Compared with that in nontransfected controls, cell proliferation, adhesion, and migration, as well as vimentin protein expression and levels of phosphorylated JAK2/STAT3, were significantly decreased (P<0.05) in A549 lung adenocarcinoma cells transfected with STIP1 shRNA, whereas E-cadherin protein expression and rates of apoptosis were significantly increased in these cells (P< 0.05).

Conclusion

Elevated expression of STIP1 in lung adenocarcinoma may enhance the proliferative, adhesive, and migratory ability, and reduce the apoptosis of lung adenocarcinoma cells through the JAK2/STAT3 signaling pathway and epithelial-mesenchymal transition (EMT), thereby promoting the recurrence and metastatic potential of this cancer. The results indicate that STIP1 may be an effective therapeutic target for the treatment of lung adenocarcinoma.

BRAF Mutation in Colorectal Rhabdoid and Poorly Differentiated Medullary Carcinomas

Colorectal rhabdoid carcinomas (CRbCs) are very rare and aggressive cancers. The BRAF mutation and CpG island methylator phenotype have been reported to be common features of CRbCs. This study reviews the literature about CRbCs and analyzes the clinicopathological and molecular profiles of seven CRbCs characterized by large discohesive cells with abundant eosinophilic cytoplasm, showing hyaline inclusions and large rounded to bean-shaped nuclei. For comparison, we included four poorly differentiated medullary carcinomas (PDMCs) with focal aspects mimicking rhabdoid features. Overall survival was poor in both subsets, with 78% of patients dying of disease within 2–11 months. The main features of CRbCs were: Loss of/reduced SMARCB1/INI expression, intense vimentin immunostaining, and dense neutrophilic infiltration. The PDMCs were positive for pancytokeratin but negative for vimentin and showed moderate peritumoral/intratumoral CD8+ lymphocytes. All PDMCs showed SMARCB1(INI-1) expression. The coexistence of BRAF and TP53 mutations was observed in 80% of CRbCs and PDMCs. PDMCs always showed microsatellite instability and CpG island methylator phenotype (CIMP), while CRbCs were CIMP negative and exhibited microsatellite instability (MSI) in two out of seven cases. CRbCs are characterized by BRAF and TP53 mutations. Loss/reduced expression of nuclear SMARCB1/INI, intense vimentin immunostaining, dense neutrophilic infiltration, and low frequency of CIMP are useful markers to recognize these rare aggressive tumors.

Correlation of clinicopathological features and LGR5 expression in colon adenocarcinoma

Colon cancer stem cells (CSCs) are closely related to tumorigenesis and treatment response, and LGR5 is currently the most robust and reliable CSC marker in colorectal cancer (CRC). However, LGR5 expression in CRC tumor budding (TB) is not well understood. We examined the clinicopathological and prognostic significance of LGR5 in CRC TB. LGR5 expression was evaluated by RNAscope, a newly developed RNA in situ hybridization technique, using a tissue microarray consisting of 55 patient samples of TB in colon adenocarcinoma (CA) selected from the medical archives at our hospital. Patients were stratified into negative and positive LGR5 expression groups. Inflammatory cell infiltration was weaker and histological grade was lower in the LGR5-positive group compared with the LGR5-negative group (P = 0.0407 and P = 0.0436, respectively). There was a significant difference in OS between the LGR5-positive group and LGR5-negative group (log-rank test, P = 0.0088). Cox proportional hazards models revealed that the LGR5-positive group (Overall survival (OS) = 0.37, 95% CI: 0.17-0.79, P = 0.0101) had better OS. LGR5 expression may be affected by inflammatory cell infiltration in the budding area of CA and is an important potential marker of prognosis.

The Prognostic and Clinical Value of CD44 in Colorectal Cancer: A Meta-Analysis

Background: CD44 is widely used as a putative cancer stem cells (CSCs) marker for colorectal cancer (CRC). However, the prognostic role of CD44 in CRC remains controversial. Methods: We performed a systematic review and meta-analysis to evaluate the association of various CD44 isoforms and overall survival (OS) and clinicopathological features of CRC patients. Results: A total of 48 studies were included in the meta-analysis. Total CD44 isoforms overexpression was significantly correlated with worse OS of patients with CRC (HR = 1.32, 95% CI = 1.08-1.61, P = 0.007). In a stratified analysis, a higher level of either CD44v6 or CD44v2 had an unfavorable impact on OS (HR_CD44v6 = 1.50, 95% CI = 1.10-2.14, P = 0.010; HR_CD44v2 = 2.93, 95% CI = 1.49-5.77, P = 0.002). Additionally, CD44 was shown to be associated with some clinicopathological features, such as lymph node metastasis (OR_CD44 = 1.56, 95% CI = 1.01-2.41, P = 0.044; OR_CD44v6 = 1.97, 95% CI = 1.19-3.26, P = 0.008; OR_{Total CD44 isoforms} = 1.57, 95% CI = 1.15-2.14, P = 0.004), distant metastasis (OR_CD44 = 2.90, 95% CI = 1.08-7.83, P = 0.035; OR_{Total CD44 isoforms} = 1.89, 95% CI = 1.02-3.53, P = 0.044). Moreover, a high level of CD44 showed a possible correlation with poor differentiation (OR_{Total CD44 isoforms} = 1.44, 95% CI = 1.00-2.08, P = 0.051), elevated level of CD44v6 tend to be correlated with tumor size (OR = 1.71, 95% CI = 0.99-2.96, P = 0.056). Conclusions: This meta-analysis demonstrated that CD44 overexpression might be an unfavorable prognostic factor for CRC patients and could be used to predict poor differentiation, lymph node metastasis and distant metastasis.

The Immunohistochemical Pattern of Epithelial-Mesenchymal Transition Markers In Endometrial Carcinoma

The majority of endometrial carcinoma are diagnosed at an early stage and exhibit a favorable prognosis. However, 10% to 15% of ECs recur and the majority are type II tumors which are high-grade carcinomas. The epithelial-mesenchymal transition (EMT) has been considered as a fundamental step for the development of the invasive phenotype of cancer cells. During EMT, many of epithelial surface markers, primarily E-cadherin disappear, and mesenchymal markers including N-cadherin gain. This feature resides predominantly at the invasive front (IF) of the tumor. Therefore, we examined the immunohistochemical expression of E-cadherin and N-cadherin at the IF, in central areas of the tumor and lymphovascular space, in type I and type II endometrial carcinoma. The association of each protein with the clinicopathologic features was also evaluated. Our results confirmed a stronger E-cadherin immunostaining in type I tumors indicating that the loss of E-cadherin may be responsible for a more aggressive behavior of type II ECs. In both types, E-cadherin was strongly expressed in central areas and the reactivity decreased toward the IF. On contrary, N-cadherin was overexpressed at the IF confirming an inverse relationship between these markers. In addition, a decrease in E-cadherin expression was observed in cells within the lymphovascular space. Downregulation of E-cadherin was associated only with high-grade tumors while no correlations between both markers and other clinicopathologic features were found. Our results confirm that EMT occurs at the IF that represents a critical interface between the tumor and the host.

Prognostic impact of microscopic vessel invasion and visceral pleural invasion and their correlations with epithelial-mesenchymal transition, cancer stemness, and treatment failure in lung adenocarcinoma

OBJECTIVES

Microscopic vessel invasion (MVI) and visceral pleural invasion (VPI) have been recently reported as poor prognostic factors of non-small cell lung cancer. Epithelial-mesenchymal transition (EMT) and cancer stemness (CS) are known malignant phenotypes that induce resistance to cancer therapy. We aimed to assess the prognostic significance of MVI and the correlations among VPI/MVI, EMT, CS, and treatment failure for recurrent tumor.

MATERIALS AND METHODS

From 2002 to 2013, 1034 consecutive patients with pathological T1-4N0-2M0 lung adenocarcinoma underwent complete resection. Moreover, we established 206 tissue microarray (TMA) samples from 2002 to 2007. We then evaluated the prognostic impact of MVI, including conventional clinicopathological factors, and analyzed the VPI/MVI, EMT, CS, and treatment failure by TMA immunohistochemical staining.

RESULTS

Among the 1034 cases, the proportion of patients with a 5-year overall survival (OS) period was 63.9% and 88.2% (MVI: +/-; p < .001). Multivariate analysis revealed that both MVI and VPI were independent predictors of OS (HR 1.57 and 1.47, respectively). Significant separation of the OS rate curves was observed among the 3 groups [VPI/MVI: both positive (2), either positive (1), and both negative (0)]. Among the 206 TMA cases, these 3 groups of VPI/MVI were significantly correlated with EMT and CS. The median time to progression after recurrence were 3.8, 8.9, and 15.9 months, respectively (VPI/MVI: 2/1/0; p =  0.016).

CONCLUSION

MVI and VPI are significant prognostic factors of lung cancer, and they are correlated with EMT, CS, and treatment failure for recurrent tumor.

Epidermal growth factor induces STAT1 expression to exacerbate the IFNr-mediated PD-L1 axis in epidermal growth factor receptor-positive cancers

The epidermal growth factor (EGF) receptor (EGFR) overexpressed in many cancers, including lung and head and neck cancers, and is involved in cancer cell progression and survival. PD-L1, increases in tumor cells to evade and inhibit CD8+ T cells, is a clinical immunotherapeutic target. This study investigated the molecular mechanism of EGF on regulating PD-L1 in EGFR-positive cancers and determined potential agents to reduce PD-L1 expression. RNA sequencing (RNAseq) and bioinformatics analysis were performed to determine potential driver genes that regulate PD-L1 in tumor cells-derived tumorspheres which mimicking cancer stem cells. Then, the specific inhibitors targeting EGFR were applied to reduce the expression of PD-L1 in vitro and in vivo. We validated that EGF could induce PD-L1 expression in the selected EGFR-positive cancers. RNAseq results revealed that STAT1 increased as a driver gene in KOSC-3-derived tumorspheres; these data were analyzed using PANTHER followed by NetworkAnalyst. The blockade of EGFR by afatinib resulted in decreased STAT1 and IRF-1 levels, both are transcriptional factors of PD-L1, and disabled the IFNr-STAT1-mediated PD-L1 axis in vitro and in vivo. Moreover, STAT1 knockdown significantly reduced EGF-mediated PD-L1 expression, and ruxolitinib, a JAK1/JAK2 inhibitor, significantly inhibited STAT1 phosphorylation to reduce the IFNr-mediated PD-L1 axis. These results indicate that EGF exacerbates PD-L1 by increasing the protein levels of STAT1 to enforce the IFNr-JAK1/2-mediated signaling axis in selected EGFR-positive cancers. The inhibition of EGFR by afatinib significantly reduced PD-L1 and may be a potential strategy for enhancing immunotherapeutic efficacy.

STAT3 exacerbates survival of cancer stem-like tumorspheres in EGFR-positive colorectal cancers: RNAseq analysis and therapeutic screening

Background

Cancer stem cells are capable of undergoing cell division after surviving cancer therapies, leading to tumor progression and recurrence. Inhibitory agents against cancer stem cells may be therapeutically used for efficiently eradicating tumors. Therefore, the aim of this study was to identify the relevant driver genes that maintain cancer stemness in epidermal growth factor receptor (EGFR)-positive colorectal cancer (CRC) cells and to discover effective therapeutic agents against these genes.

Methods

In this study, EGFR-positive cancer stem-like cells (CSLCs) derived from HCT116 and HT29 cells were used as study models for in vitro inductions. To identify the differential genes that maintain CSLCs, RNAseq analysis was conducted followed by bioinformatics analysis. Moreover, a panel containing 172 therapeutic agents targeting the various pathways of stem cells was used to identify effective therapeutics against CSLCs.

Results

RNAseq analysis revealed that 654 and 840 genes were significantly upregulated and downregulated, respectively, in the HCT116 CSLCs. Among these genes, notably, platelet-derived growth factor A (PDGFA) and signal transducer and activator of transcription 3 (STAT3) were relevant according to the cancer pathway analyzed using NetworkAnalyst. Furthermore, therapeutic screening revealed that the agents targeting STAT3 and Wnt signaling pathways were efficient in reducing the cell viabilities of both HCT116 and HT29 cells. Consequently, we discovered that STAT3 inhibition using homoharringtonine and STAT3 knockdown significantly reduced the formation and survival of HT29-derived tumorspheres. We also observed that STAT3 phosphorylation was regulated by epidermal growth factor (EGF) to induce PDGFA and Wnt signaling cascades.

Conclusions

We identified the potential genes involved in tumorsphere formation and survival in selective EGFR-positive CRCs. The results reveal that the EGF-STAT3 signaling pathway promotes and maintains CRC stemness. In addition, a crosstalk between STAT3 and Wnt activates the Wnt/β-catenin signaling pathway, which is also responsible for cancer stemness. Thus, STAT3 is a putative therapeutic target for CRC treatment.

Electronic supplementary material

The online version of this article (10.1186/s12929-018-0456-y) contains supplementary material, which is available to authorized users.

High Vimentin Expression Predicts a Poor Prognosis and Progression in Colorectal Cancer: A Study with Meta-Analysis and TCGA Database

The aim of this study was to evaluate the role of vimentin expression in the prognosis and progression of CRC. Meta-analysis was conducted to investigate the correlations between vimentin and prognosis and clinicopathological features in CRC. Literatures were searched by PubMed, Embase, ClinicalKey, CNKI, VIP, and WanFang databases. The Cancer Genome Atlas (TCGA) database was used to assess the association of vimentin expression with survival rate in CRC. Eleven reports with 1969 cases were included in the meta-analysis. The results showed that positive vimentin expression predicted a poor overall survival (OS) in the univariate analysis (HR: 2.087, 95%CI: 1.660-2.625) and multivariate analysis (HR: 1.633, 95%CI: 1.223-2.181). Vimentin overexpression also conferred worse disease-free survival (DFS) in the univariate analysis (HR: 2.069, 95%CI: 1.024-4.179) and multivariate analysis (HR: 2.802, 95%CI: 1.421-5.527). Moreover, upregulated vimentin is related to lymph node metastasis (OR: 2.288, 95%CI: 1.159-4.517), TNM stages (OR: 1.957, 95%CI: 1.333-2.873), and N stage (OR: 2.316, 95%CI: 1.482-3.620). Analysis of TCGA database indicated that elevated vimentin predicated a shorter OS (p=0.033). Our findings reveal that upregulated vimentin contributes to the progression and poor prognosis of CRC. Vimentin may be a prognostic biomarker and therapeutic target in patients with CRC.

Suppression of cancer stemness by upregulating Ligand-of-Numb protein X1 in colorectal carcinoma

Cancer stem-like cells (CSCs) have been reported to play major roles in tumorigenesis, tumor relapse, and metastasis after therapy against colorectal carcinoma (CRC). Therefore, identification of colorectal CSC regulators could provide promising targets for CRC. Ligand-of-Numb protein X1 (LNX1) is one E3 ubiquitin ligase which mediates the ubiquitination and degradation of Numb. Although several studies indicate LNX1 could be a potential suppressor of cancer diseases, the functions of LNX1 in mediating cancer stemness remain poorly understood. In this study, LNX1 was identified as a negative regulator of cancer stemness in CRC, which was downregulated in colonospheres or side population (SP) cells. Furthermore, the coxsackievirus and adenovirus receptor (CXADR) was found to be one critical downstream mediator of cancer stemness regulated by LNX1. Interestingly, the anti-breast cancer drug tamoxifen was found to be an agonist of LNX1 and suppress cancer stemness in CRC. In sum, this study provided the evidences that LNX1 signaling plays important roles in regulating the stemness of colon cancer cells.