The role of Snail1 transcription factor in colorectal cancer progression and metastasis

Biochemical implications of robotic surgery: a new frontier in the operating room

Robotic surgery represents a milestone in surgical procedures, offering advantages such as less invasive methods, elimination of tremors, scaled motion, and 3D visualization. This in-depth analysis explores the complex biochemical effects of robotic methods. The use of pneumoperitoneum and steep Trendelenburg positioning can decrease pulmonary compliance and splanchnic perfusion while increasing hypercarbia. However, robotic surgery reduces surgical stress and inflammation by minimizing tissue trauma. This contributes to faster recovery but may limit immune function. Robotic procedures also limit ischemia-reperfusion injury and oxidative damage compared to open surgery. They also help preserve native antioxidant defenses and coagulation. In a clinical setting, robotic procedures reduce blood loss, pain, complications, and length of stay compared to traditional procedures. However, risks remain, including device failure, the need for conversion to open surgery and increased costs. On the oncology side, there is still debate about margins, recurrence, and long-term survival. The advent of advanced technologies, such as intraoperative biosensors, localized drug delivery systems, and the incorporation of artificial intelligence, may further improve the efficiency of robotic surgery. However, ethical dilemmas regarding patient consent, privacy, access, and regulation of this disruptive innovation need to be addressed. Overall, this review sheds light on the complex biochemical implications of robotic surgery and highlights areas that require additional mechanistic investigation. It presents a comprehensive approach to responsibly maximize the potential of robotic surgery to improve patient outcomes, integrating technical skill with careful consideration of physiological and ethical issues.

MSCs can be a double-edged sword in tumorigenesis

Mesenchymal stem cells (MSCs) have been used to treat various diseases including Alzheimer's disease and cancer. In particular, the immunomodulatory function of MSCs plays a major role in cancer therapy using stem cells. However, MSCs exert promotive and inhibitory effects on cancer. The immunomodulatory effects of MSCs in the tumor microenvironment (TME) are ambiguous, which is the primary reason for the different outcomes of MSCs therapies for tumors. This review discusses the use of MSCs in cancer immunotherapy and their immunomodulatory mechanisms in cancers.

Immunohistochemical expression of Snail1 protein in colorectal adenocarcinoma samples and its prognostic activity in Caucasian patients

Introduction

The current study investigated the expression of Snail1 protein in colon adenocarcinoma samples to assess its prognostic significance by correlating its expression with the clinicopathological variables and survival of Caucasian patients.

Aim

To investigate the clinicopathological and prognostic roles of Snail1 expression, the immunohistochemical analysis was performed in colon tumour tissues and adjacent non- pathological mucosa.

Material and methods

It should be noted that only trace expression of this protein was revealed in adjacent non-tumour colorectal mucosa, whereas the high expression was demonstrated in well differentiated, moderately differentiated, and poorly differentiated tumours.

Results

The Kaplan-Meier survival analysis showed that the overall survival rate in the group of patients with a low expression level of Snail1 was significantly longer than that for patients with a moderate or strong level of Snail1 immunoreactivity (p < 0.001). The 5-year overall survival for patients with a low, moderate, or strong level of Snail1 immunoexpression was 100%, 25.7%, and 2%, respectively. The Snail1-moderate patients had an average survival time of 44.886 months (95% CI: 40.855–48.916), whereas the Snail1-strong expression groups had an average survival time of 21.706 (95% CI: 17.863–25.549). The statistical analysis revealed that the level of the Snail1 immunohistochemical reactivity was correlated with the grade of the histological differentiation. A multivariate analysis demonstrated that the grade of tumour differentiation (HR = 2.150; 95% CI: 1.380–3.349, p = 0.001) and Snail1 expression (HR = 3.901; 95% CI: 2.436–6.247, p < 0.001) were the independent risk factors for worse survival.

Conclusions

In colon adenocarcinoma patients, the expression of Snail1 may act as the independent risk factors for worse survival.

Diversity of Epithelial-Mesenchymal Phenotypes in Circulating Tumour Cells from Prostate Cancer Patient-Derived Xenograft Models

Simple Summary

Spread of prostate cancer to other parts of the body is responsible for the majority of deaths. Tumour cell epithelial mesenchymal plasticity (EMP) increases their metastatic potential and facilitates their survival in the blood as circulating tumour cells (CTCs). The aim of this study was to molecularly characterise CTCs in a panel of prostate cancer patient-derived xenografts using genes associated with epithelial and mesenchymal phenotypes, and to compare the EMP status of CTCs with their matched primary tumours. The study highlights high heterogeneity in CTC enumeration and EMP gene expression between tumour-bearing mice and within individual blood samples, and therefore caution should be taken when interpreting pooled CTC analyses. Critically, tumour cells were present in the epithelial-mesenchymal hybrid state in the circulation. The study also demonstrates that there is high variation in CTC size, which would introduce sample bias to size-based CTC isolation techniques.

Abstract

Metastasis is the leading cause of cancer-related deaths worldwide. The epithelial-mesenchymal plasticity (EMP) status of primary tumours has relevance to metastatic potential and therapy resistance. Circulating tumour cells (CTCs) provide a window into the metastatic process, and molecular characterisation of CTCs in comparison to their primary tumours could lead to a better understanding of the mechanisms involved in the metastatic cascade. In this study, paired blood and tumour samples were collected from four prostate cancer patient-derived xenograft (PDX) models (BM18, LuCaP70, LuCaP96, LuCaP105) and assessed using an EMP-focused, 42 gene human-specific, nested quantitative RT-PCR assay. CTC burden varied amongst the various xenograft models with LuCaP96 having the highest number of CTCs per mouse (mean: 704; median: 31) followed by BM18 (mean: 101; median: 21), LuCaP70 (mean: 73; median: 16) and LuCaP105 (mean: 57; median: 6). A significant relationship was observed between tumour size and CTC number (p = 0.0058). Decreased levels of kallikrein-related peptidase 3 (KLK3) mRNA (which encodes prostate-specific antigen; PSA) were observed in CTC samples from all four models compared to their primary tumours. Both epithelial- and mesenchymal-associated genes were commonly expressed at higher levels in CTCs compared to the bulk primary tumour, although some common EMT-associated genes (CDH1, VIM, EGFR, EPCAM) remained unchanged. Immunofluorescence co-staining for pan-cytokeratin (KRT) and vimentin (VIM) indicated variable proportions of CTCs across the full EMP axis, even in the same model. EMP hybrids predominated in the BM18 and LuCaP96 models, but were not detected in the LuCaP105 model, and variable numbers of KRT⁺ and human VIM⁺ cells were observed in each model. SERPINE1, which encodes plasminogen activator inhibitor-1 (PAI-1), was enriched at the RNA level in CTCs compared to primary tumours and was the most commonly expressed mesenchymal gene in the CTCs. Co-staining for SERPINE1 and KRT revealed SERPINE1⁺ cells in 7/11 samples, six of which had SERPINE⁺KRT⁺ CTCs. Cell size variation was observed in CTCs. The majority of samples (8/11) contained larger CTCs ranging from 15.3 to 37.8 µm, whilst smaller cells (10.7 ± 4.1 µm, similar in size to peripheral blood mononuclear cells (PBMCs)) were identified in 6 of 11 samples. CTC clusters were also identified in 9/11 samples, containing 2–100 CTCs per cluster. Where CTC heterogeneity was observed in the clusters, epithelial-like cells (KRT⁺VIM⁻) were located on the periphery of the cluster, forming a layer around hybrid (KRT⁺VIM⁺) or mesenchymal-like (KRT⁻VIM⁺) cells. The CTC heterogeneity observed in these models emphasises the complexity in CTC isolation and classification and supports the increasingly recognised importance of the epithelial-mesenchymal hybrid state in cancer progression and metastasis.

The Role of Snail-1 in Thyroid Cancer-What We Know So Far

Thyroid carcinomas, despite the usually indolent behaviour and relatively good overall prognosis, show a high tendency to gain invasive phenotype and metastasise in some cases. However, due to a relatively slow progression, the exact mechanisms governing the metastatic process of thyroid carcinomas, including the epithelial-to-mesenchymal transition (EMT), are poorly described. One of the best-known regulators of cancer invasiveness is Snail-1-a zinc-finger transcription factor that plays a key role as an EMT inducer. More and more attention is being paid to the role of Snail with regard to thyroid cancer development. Apart from the obvious implications in the EMT process, Snail-1 plays an important role in the regulation of chemoresistance of the thyroid cells and cancer stem cell (CSC) formation, and it also interacts with miRNA specific to the thyroid gland. The aim of this review was to summarise the knowledge on Snail-1, especially in the context of thyroid oncogenesis.

Snail-1 Overexpression Correlates with Metastatic Phenotype in BRAFV600E Positive Papillary Thyroid Carcinoma

The ability of cancer to metastasize is regulated by various signaling pathways, including transforming growth factor β (TGFβ), also implicated in the upregulation of Snail-1 transcription factor in malignant neoplasms. B-type Raf kinase gene (BRAF)V600E, the most common driving mutation in papillary thyroid carcinoma (PTC), induces epithelial to mesenchymal transition (EMT) in thyroid cancer cells through changes in the Snail-1 level, increasing cell migration and invasion. However, little is known about the mechanism of Snail-1 and BRAFV600E relations in humans. Our study included 61 PTC patients with evaluated BRAFV600E mutation status. A total of 18 of those patients had lymph node metastases-of whom 10 were BRAFV600E positive, and 8 negative. Our findings indicate that the expression of Snail-1, but not TGFβ1, correlates with the metastatic phenotype in PTC. This is the first piece of evidence that the upregulation of Snail-1 corresponds with the presence of BRAFV600E mutation and increased expression of Snail-1 in metastatic PTC samples is dependent on BRAFV600E mutation status.

AXIN2 and SNAIL expression predict the risk of recurrence in cutaneous squamous cell carcinoma after Mohs micrographic surgery

Recurrence is a common complication observed during cutaneous squamous cell carcinoma (cSCC) treatment; however, biomarkers for predicting recurrence in cSCC remain unknown. The present study aimed to investigate the predictive value of axis inhibition protein 2 (AXIN2) and SNAIL expression in cSCC recurrence. AXIN2 and SNAIL expression was evaluated using immunohistochemistry in 111 cSCC tissue samples obtained from 18 patients who presented recurrence (recurrence interval, 1–91 months) and 93 patients who did not experience recurrence following Mohs micrographic surgery (MMS) during the follow-up period (156 months). Nomogram construction was performed using patients' clinicopathological characteristics and AXIN2 and SNAIL protein expression. The results demonstrated that high AXIN2 (histoscore >100) and SNAIL (histoscore >100) expression was detected in 35 and 44 cSCC tissues, respectively. Furthermore, the expression levels of AXIN2 and SNAIL were significantly associated in patients with cSCC (P=0.001). AXIN2 and SNAIL expression levels were significantly associated with tumor size (P=0.021 and P=0.044, respectively) and recurrence of cSCC (P=0.017 and P=0.042, respectively). In addition, the results of the Kaplan-Meier curve analysis revealed that recurrence-free survival was significantly associated with tumor size (P=0.025), differentiation status (P<0.001), AXIN2 expression (P=0.001) and SNAIL expression (P=0.001). Furthermore, the results of the multivariate analysis demonstrated that age (P=0.043), AXIN2 expression (P=0.001) and SNAIL expression (P=0.045) were independent risk factors for cSCC recurrence in the present cohort. A nomogram for predicting the 1-, 2-, 3-, and 5-year recurrence-free survival was developed for patients with cSCC by including independent risk factors with a concordance index of 0.75. The results suggested that high AXIN2 and SNAIL expression may be considered as potential risk factors for cSCC recurrence. This nomogram may therefore be useful to assess the probability of recurrence in patients with cSCC following MMS.

COUP-TFII in Health and Disease

The nuclear receptors (NRs) belong to a vast family of evolutionary conserved proteins acting as ligand-activated transcription factors. Functionally, NRs are essential in embryogenesis and organogenesis and in adulthood they are involved in almost every physiological and pathological process. Our knowledge of NRs action has greatly improved in recent years, demonstrating that both their expression and activity are tightly regulated by a network of signaling pathways, miRNA and reciprocal interactions. The Chicken Ovalbumin Upstream Promoter Transcription Factor II (COUP-TFII, NR2F2) is a NR classified as an orphan due to the lack of a known natural ligand. Although its expression peaks during development, and then decreases considerably, in adult tissues, COUP-TFII is an important regulator of differentiation and it is variably implicated in tissues homeostasis. As such, alterations of its expression or its transcriptional activity have been studied and linked to a spectrum of diseases in organs and tissues of different origins. Indeed, an altered COUP-TFII expression and activity may cause infertility, abnormality in the vascular system and metabolic diseases like diabetes. Moreover, COUP-TFII is actively investigated in cancer research but its role in tumor progression is yet to be fully understood. In this review, we summarize the current understanding of COUP-TFII in healthy and pathological conditions, proposing an updated and critical view of the many functions of this NR.

The effects of c-Src kinase on EMT signaling pathway in human lens epithelial cells associated with lens diseases

Background

The signaling pathway of epithelial to mesenchymal transition (EMT) is regulated by c-Src kinase in many cells. The purpose of this study was to investigate the effects of c-Src kinase on EMT of human lens epithelial cells in vivo stimulated by different factors.

Methods

Human lens epithelial cells, HLE-B3, were exposed to either an inflammatory factor, specifically IL-1α, IL-6, TNF-α or IL-1β, at 10 ng/mL or high glucose (35.5 mM) for 30 mins. Activity of c-Src kinase was evaluated by the expression of p-Src⁴¹⁸ with western blot assay. To investigate the effects of activation of c-Src on EMT, HLE-B3 cells were transfected with pCDNA3.1-Src^Y530F to upregulate activity of c-Src kinase, and pSlience4.1-ShSrc to knock it down. The expressions of c-Src kinase and molecular markers of EMT such as E-cadherin, ZO-1, α-SMA, and Vimentin were examined at 48 h by RT-PCR and western blot. At 48 h and 72 h of transfection, cell proliferation was detected by MTT, and cell mobility and migration were determined by scratch and transwell assays.

Results

Activity of c-Src kinase, which causes the expression of p-Src⁴¹⁸, was upregulated by different inflammatory factors and high glucose in HLE-B3 cells. When HLE-B3 cells were transfected with pCDNA3.1-Src^Y530F, the expression of c-Src kinase was upregulated on both mRNA and protein levels, and activity of c-Src kinase, expression of p-Src⁴¹⁸ increased. The expressions of both E-cadherin and ZO-1 were suppressed, while the expressions of vimentin and α-SMA were elevated on both mRNA and protein levels at the same time. Cell proliferation, mobility and migration increased along with activation of c-Src kinase. Conversely, when HLE-B3 cells were transfected with pSlience4.1-ShSrc, both c-Src kinase and p-Src⁴¹⁸ expressions were knocked down. The expressions of E-cadherin and ZO-1 increased, but the expressions of Vimentin and α-SMA decreased; meanwhile, cell proliferation, mobility and migration reduced.

Conclusions

The c-Src kinase in lens epithelial cells is easily activated by external stimuli, resulting in the induction of cell proliferation, mobility, migration and EMT.

Apigenin inhibits epithelial-mesenchymal transition of human colon cancer cells through NF-κB/Snail signaling pathway

Colon cancer is a leading cause of cancer-related deaths worldwide. The epithelial-mesenchymal transition (EMT) plays an important role in tumor metastasis of colon cancer. We first evaluated the effects of EMT-related transcription factors on the prognosis of colon cancer through analysis the data obtained from The Cancer Genome Atlas (TCGA). And then we screened a series of Chinese medicine monomers to find effect EMT inhibitors. First, Snail is a more important EMT transcription factors for colon cancer prognosis, compared with Twist and Slug. Then, we found that apigenin effectively inhibits the activity of Snail. Apigenin could inhibit the EMT, migration, and invasion of human colon cancer cells in vitro and in vivo through the NF-κB/Snail pathway. Snail is a key regulator of EMT in colon cancer and Snail inhibitor apigenin may be a therapeutic application for patients with colon cancer.

Nicotine promotes cervical metastasis of oral cancer by regulating peroxiredoxin 1 and epithelial-mesenchymal transition in mice

Background

Tobacco is a major risk factor for oral squamous cell carcinoma (OSCC). However, the role of nicotine in OSCC is not completely understood.

Materials and methods

To analyze the mechanisms of nicotine-induced cervical metastasis, we investigated whether nicotine induced invasion, migration, and epithelial–mesenchymal transition (EMT) via regulating peroxiredoxin 1 (Prx1) in CAL 27 cells. In addition, we established a mouse model to confirm the roles of nicotine in regulating Ets1/Prx1/EMT signaling in OSCC metastasis.

Results

We showed that nicotine induced CAL 27 cell invasion, migration, EMT, and Prx1 and Ets1 expression. Prx1 knockdown inhibited cell invasion, migration, and EMT. Ets1 silencing downregulated Prx1 expression and EMT. Prx1 and Ets1 were shown to interact in CAL 27 cells treated with nicotine, and nicotine could significantly upregulate the binding of the transcription factor Ets1 to the Prx1 gene promoter region. Additionally, an in vivo study showed that nicotine induced tumor metastasis and EMT. Prx1 knockdown inhibited cervical metastasis rates and EMT progression. No significant differences in metastasis rates and EMT-related marker expression levels were observed between vehicle- and nicotine-treated mice.

Conclusion

The results indicate that nicotine promotes cervical lymph node metastasis through regulating Ets1/Prx1/EMT signaling during OSCC pathogenesis; consequently, Prx1 may represent a potential target for the prevention and treatment of OSCC.

Human adipose‑derived mesenchymal stem cells promote breast cancer MCF7 cell epithelial‑mesenchymal transition by cross interacting with the TGF‑β/Smad and PI3K/AKT signaling pathways

The influence and underlying mechanisms of human adipose-derived stem cells (Hu-ADSCs) on breast cancer cells in the tumor microenvironment remain unclear. Understanding the association between Hu-ADSCs and cancer cells may provide targets for breast cancer treatment and reference for the clinical application of stem cells. Therefore, a Hu-ADSC and breast cancer MCF7 cell coculture system was established to investigate the paracrine effects of Hu-ADSCs on MCF7 cell migration and invasion, in addition to the potential mechanism of action by reverse transcription-quantitative polymerase chain reaction and western blotting. Hu-ADSCs enhanced MCF7 cell migration and invasion by decreasing the expression of epithelial marker E-cadherin, and increasing the expression of interstitial marker N-cadherin and epithelial-mesenchymal transition (EMT) transcription factors in vitro. The EMT effect of cocultured MCF7 cells was inhibited with the addition of anti-transforming growth factor (TGF)-β1 or phosphoinositide 3-kinase (PI3K) inhibitor LY294002, accompanied by a significant decrease in phosphorylated (p)-mothers against decapentaplegic homolog (Smad) and p-protein kinase B (AKT) expression. The data suggested that the paracrine effect of Hu-ADSCs in the tumor microenvironment promoted the EMT of MCF7 cells by cross interacting with the TGF-β/Smad and PI3K/AKT pathways.

Enhanced PAPSS2/VCAN sulfation axis is essential for Snail-mediated breast cancer cell migration and metastasis

The zinc finger protein Snail is a master regulator of epithelial-mesenchymal transition (EMT) and a strong inducer of tumor metastasis, yet the signal cascades triggered by Snail have not been completely revealed. Here, we report the discovery of the sulfation program that can be induced by Snail in breast cancer cells, and which plays an essential role in cell migration and metastasis. Specifically, Snail induces the expression of PAPSS2, a gene that encodes a rate-limiting enzyme in sulfation pathway, and VCAN, a gene that encodes the chondroitin sulfate proteoglycan Versican in multiple breast cancer cells. Depletion of PAPSS2 in MCF7 and MDA-MB-231 cells results in reduced cell migration, while overexpression of PAPSS2 promotes cell migration. Moreover, MDA-MB-231-shPAPSS2 cells display a significantly lower rate of lung metastasis and lower number of micrometastatic nodules in nude mice, and conversely, MDA-MB-231-PAPSS2 cells increase lung metastasis. Similarly, depletion of VCAN dampens the cell migration activity induced by Snail or PAPSS2 in MCF 10A cells. Moreover, PAPSS inhibitor sodium chlorate effectively decreases cell migration induced by Snail and PAPSS2. More importantly, the expression of Snail, PAPSS2, and VCAN is positively correlated in breast cancer tissues. Together, these findings are important for understanding the genetic programs that control tumor metastasis and may identify previously undetected therapeutic targets to treat metastatic disease.

Twist1-induced epithelial-mesenchymal transition according to microsatellite instability status in colon cancer cells

Colorectal cancer (CRC) with microsatellite instability (MSI) may exhibit impaired epithelial-mesenchymal transition (EMT), but little is known about the underlying mechanisms of this phenomenon. In this study, we investigated the role of Twist1 and its downstream signaling cascades in EMT induction according to MSI status. To investigate the effects of Twist1 on EMT induction according to MSI status, MSS LS513 and MSI LoVo colon cancer cell lines, which overexpress human Twist1, were generated. Twist1-induced EMT and its downstream signaling pathways were evaluated via in vitro and in vivo experiments. We found that Twist1 induced EMT markers and stem cell-like characteristics via AKT signaling pathways. Twist1 induced activation of AKT and suppression of glycogen synthase kinase (GSK)-3β, which resulted in the activation of β-catenin, increasing CD44 expression. In addition, Twist1 activated the AKT-induced NF-κB pathway, increasing CD44 and CD166 expression. Activation of both the AKT/GSK-3β/β-catenin and AKT/NF-κB pathways occurred in MSS LS513 cells, while only the AKT/GSK-3β/β-catenin pathway was activated in MSI LoVo cells. In conclusion, Twist1 induces stem cell-like characteristics in colon cancer cell lines related to EMT via AKT signaling pathways, and those pathways depend on MSI status.

3,3'-Diindolylmethane Suppressed Cyprodinil-Induced Epithelial-Mesenchymal Transition and Metastatic-Related Behaviors of Human Endometrial Ishikawa Cells via an Estrogen Receptor-Dependent Pathway

Cyprodinil (CYP) is a pyrimidine amine fungicide that has been extensively used in agricultural areas. 3,3′-Diindolylmethane (DIM) is a derivative of the dietary phytoestrogen, indole-3-carbinol (I3C), which is derived from cruciferous vegetables and considered to be a cancer-preventive phytonutrient agent. In this study, the effects of CYP and DIM were examined on the cell viability, invasion, and metastasis of human endometrial cancer cells, Ishikawa, via epithelial mesenchymal transition (EMT). CYP increased the level of cell viability of Ishikawa cells compared to DMSO as a control, as did E2. Ishikawa cells lost cell-to-cell contact and obtained a spindle-shaped or fibroblast-like morphology in response to the application of E2 or CYP by the cell morphology assay. In the cell migration and invasion assay, CYP enhanced the ability of migration and invasion of Ishikawa cells, as did E2. E2 and CYP increased the expressions of N-cadherin and Snail proteins, while decreasing the expression of E-cadherin protein as EMT-related markers. In addition, E2 and CYP increased the protein expressions of cathepsin D and MMP-9, metastasis-related markers. Conversely, CYP-induced EMT, cell migration, and invasion were reversed by fulvestrant (ICI 182,780) as an estrogen receptor (ER) antagonist, indicating that CYP exerts estrogenic activity by mediating these processes via an ER-dependent pathway. Similar to ICI 182,780, DIM significantly suppressed E2 and CYP-induced proliferation, EMT, migration, and invasion of Ishikawa cancer cells. Overall, the present study revealed that DIM has an antiestrogenic chemopreventive effect to withdraw the cancer-enhancing effect of E2 and CYP, while CYP has the capacity to enhance the metastatic potential of estrogen-responsive endometrial cancer.

The anti-tumorigenic activity of A2M-A lesson from the naked mole-rat

Cancer resistance is a major cause for longevity of the naked mole-rat. Recent liver transcriptome analysis in this animal compared to wild-derived mice revealed higher expression of alpha2-macroglobulin (A2M) and cell adhesion molecules, which contribute to the naked mole-rat’s cancer resistance. Notably, A2M is known to dramatically decrease with age in humans. We hypothesize that this might facilitate tumour development. Here we found that A2M modulates tumour cell adhesion, migration and growth by inhibition of tumour promoting signalling pathways, e.g. PI3K / AKT, SMAD and up-regulated PTEN via down-regulation of miR-21, in vitro and in tumour xenografts. A2M increases the expression of CD29 and CD44 but did not evoke EMT. Transcriptome analysis of A2M-treated tumour cells, xenografts and mouse liver demonstrated a multifaceted regulation of tumour promoting signalling pathways indicating a less tumorigenic environment mediated by A2M. By virtue of these multiple actions the naturally occurring A2M has strong potential as a novel therapeutic agent.

Snail determines the therapeutic response to mTOR kinase inhibitors by transcriptional repression of 4E-BP1

Loss of 4E-BP1 expression has been linked to cancer progression and resistance to mTOR inhibitors, but the mechanism underlying 4E-BP1 downregulation in tumors remains unclear. Here we identify Snail as a strong transcriptional repressor of 4E-BP1. We find that 4E-BP1 expression inversely correlates with Snail level in cancer cell lines and clinical specimens. Snail binds to three E-boxes present in the human 4E-BP1 promoter to repress transcription of 4E-BP1. Ectopic expression of Snail in cancer cell lines lacking Snail profoundly represses 4E-BP1 expression, promotes cap-dependent translation in polysomes, and reduces the anti-proliferative effect of mTOR kinase inhibitors. Conversely, genetic and pharmacological inhibition of Snail function restores 4E-BP1 expression and sensitizes cancer cells to mTOR kinase inhibitors by enhancing 4E-BP1-mediated translation-repressive effect on cell proliferation and tumor growth. Our study reveals a critical Snail-4E-BP1 signaling axis in tumorigenesis, and provides a rationale for targeting Snail to improve mTOR-targeted therapies.

4E-BP1 is a translational repressor critical in mTOR signaling, whereas Snail is a critical promoter of epithelial to mesenchymal transition. Here the authors show that Snail induces resistance to mTOR inhibitors by repressing 4E-BP1 expression and promoting cell cycle progression via upregulating cycD.

Combined detection of Twist1, Snail1 and squamous cell carcinoma antigen for the prognostic evaluation of invasion and metastasis in cervical squamous cell carcinoma

BACKGROUND

Cervical cancer is one of the most common malignant tumours of the female reproductive system, ranking second only to breast cancer in morbidity worldwide. Essential features of the progression of cervical cancer are invasion and metastasis, which are closely related to disease prognosis and mortality rate. At the present time there is no effective method to evaluate cancer invasion and metastasis before surgery. Here we report our study on molecular changes in biopsy tissue for the prognostic evaluation of cancer invasion and metastasis.

PATIENTS AND METHODS

Expression of the epithelial-mesenchymal transition-inducing transcription factors Twist1 and Snail1 was detected by immunohistochemistry in 32 normal, 36 low-grade squamous intraepithelial neoplasia (LSIL), 54 high-grade squamous intraepithelial neoplasia (HSIL) and 320 cervical squamous cell carcinoma (CSCC) samples. The correlation between the expression of Twist1, Snail1 and squamous cell carcinoma antigen (SCCA) in CSCC tissues and clinical pathology results was evaluated. A transwell migration and invasion assay was used to explore the roles of Twist1 and Snail1 in the invasion of cancer cells. Lymph node metastasis and lymphovascular space invasion (LVSI) rates for the following groups were analysed: SCCA(+) group, Twist1(+) group, Snail1(+) group, Twist1(+)Snail1(+)group, Twist1(+)SCCA(+)group, Snail1(+)SCCA(+)group and Twist1(+)Snail1(+)SCCA(+) group.

RESULTS

The expression of Twist1 and Snail1 was significantly upregulated in HSIL and CSCC (p < 0.05). Twist1 and Snail1 expression levels were associated with LVSI, lymph node metastasis and histological grade (p < 0.05) but not with age or FIGO stage (p > 0.05). The expression of SCCA was associated with LVSI, lymph node metastasis, FIGO stage and histological grade (p < 0.05) but not with age (p > 0.05). Twist1 was an independent factor contributing to the invasion ability of cervical cancer cells. In addition, the positive rate of lymph node metastasis and LVSI was higher in the Twist1(+)Snail1(+)SCCA(+) group than in the SCCA(+) group, Twist1(+) group and Snail1(+) group, respectively (p < 0.05).

CONCLUSION

Combined detection of Twist1 and Snail1 in SCCA-positive biopsy specimens may be a potential method for evaluating the invasion and metastasis of CSCC prior to surgery.

Crosstalk between mesenchymal stem cells and macrophages in inflammatory bowel disease and associated colorectal cancer

Mesenchymal stem cells (MSCs) are attractive seed cells for immunotherapy, tissue engineering and regenerative medicine due to their self-renewal and multidirectional differentiation abilities, diverse immunoregulatory functions and ease of isolation from a wide range of tissues. MSCs exert their immunoregulatory effect on immune cells via cell-to-cell contact and paracrine mechanisms. In turn, MSCs can also be modulated by immune cells. Macrophages are constantly present in the mucosa of the intestinal tract of mammals and play an important role in the development and progression of inflammatory bowel disease (IBD), a chronic and recurrent inflammatory disease of the gastrointestinal tract characterized by idiopathic mucosal inflammation. The increased morbidity and mortality of IBD have made it a disease hard to cure in the clinic. MSCs have emerged as an important tool for IBD therapy due to their abilities to differentiate into enterocyte-like cells and regulate inflammatory cells, especially macrophages. In this review, we discuss the recent advances in the interaction between MSCs and macrophages in diseases, with an emphasis on IBD. We propose that an optimized MSC-based therapy would provide a novel strategy for the treatment of IBD and the prevention of IBD-associated colorectal cancer (CRC).

Up-regulation of long non-coding RNA XLOC_010235 regulates epithelial-to-mesenchymal transition to promote metastasis by associating with Snail1 in gastric cancer

We previously performed long non-coding RNA (lncRNA) expression microarray analyses to identify novel indicators for gastric cancer (GC) metastasis and prognosis in which we identified lncRNA XLOC_010235 (XLOC) as a candidate RNA. However, XLOC_010235 molecular mechanism of action remains unclear. Gain and loss of function approaches were used to investigate the biological role of XLOC in vitro. The effects of XLOC on cell viability were assessed by CCK-8 proliferation assays. Real-time PCR, western-blot and immunofluorescence were used to evaluate the mRNA and protein expression of Snail and multiple EMT related molecules. The positive XLOC/Snail1 interaction was identified and verified by immunohistochemistry assay and bivariate correlation analysis. Ectopic expression of XLOC facilitate cell viability, migration and invasion, leading to the acceleration of metastasis, while depletion of XLOC expression hindered cell migration and invasion. Moreover, over-expression of XLOC was found to play a important role in epithelial-to-mesenchymal transition (EMT) through the regulation of E-cadherin, N-cadherin and Vimentin expression, in which transcriptional factor Snail1 was involved. These results advance our understanding of the role of lncRNA XLOC_010235 as a active regulator of EMT by associating with Snail1, which may help in the development of new therapeutics.

Intestinal bacterium-derived cyp27a1 prevents colon cancer cell apoptosis

The pathogenesis of metastasis of colon cancer (Cca) is to be further investigated. The dysfunction of apoptotic mechanism plays a role in the cancer cell over growth. This study tests a hypothesis by which intestinal bacterium-derived cyp27a1 prevents apoptosis in colon cancer cells. In this study, the levels of cyp27a1 in human stool samples were assessed by enzyme-linked immunosorbent assay. The apoptosis of Cca cells was observed by flow cytometry. The expression of cyp27a1 was assessed by real time RT-PCR and Western blotting. We observed higher levels of cyp27a1 in the stool samples of Cca patients than that from healthy subjects. Cca colon epithelial biopsy contained high levels of cyp27a1 protein, but not the cyp27a1 mRNA. Cyp27a1 prevented Cca cell apoptosis induced by vitamin D3. In conclusion, intestinal bacterium-derived cyp27a1 facilitates Cca survival by inhibiting Cca cell apoptosis.

Current Status of Long Non-Coding RNAs in Human Breast Cancer

Breast cancer represents a major health burden in Europe and North America, as recently published data report breast cancer as the second leading cause of cancer related death in women worldwide. Breast cancer is regarded as a highly heterogeneous disease in terms of clinical course and biological behavior and can be divided into several molecular subtypes, with different prognosis and treatment responses. The discovery of numerous non-coding RNAs has dramatically changed our understanding of cell biology, especially the pathophysiology of cancer. Long non-coding RNAs (lncRNAs) are non-protein-coding transcripts >200 nucleotides in length. Several studies have demonstrated their role as key regulators of gene expression, cell biology and carcinogenesis. Deregulated expression levels of lncRNAs have been observed in various types of cancers including breast cancer. lncRNAs are involved in cancer initiation, progression, and metastases. In this review, we summarize the recent literature to highlight the current status of this class of long non-coding lncRNAs in breast cancer.