Epithelial mesenchymal transition in colorectal cancer: Seminal role in promoting disease progression and resistance to neoadjuvant therapy

PTEN and P-4E-BP1 might be associated with postoperative recurrence of rectal cancer patients undergoing concurrent radiochemotherapy

BACKGROUND

Local recurrence after surgery and radiochemotherapy seriously affects the prognosis of locally advanced rectal cancer (LARC) patients. Studies on molecular markers related to the radiochemotherapy sensitivity of cancers have been widely carried out, which might provide valued information for clinicians to carry out individual treatment.

AIM

To find potential biomarkers of tumors for predicting postoperative recurrence.

METHODS

In this study, LARC patients undergoing surgery and concurrent radiochemotherapy were enrolled. We focused on clinicopathological factors and PTEN, SIRT1, p-4E-BP1, and pS6 protein expression assessed by immunohistochemistry in 73 rectal cancer patients with local recurrence and 76 patients without local recurrence.

RESULTS

The expression of PTEN was higher, while the expression of p-4E-BP1 was lower in patients without local recurrence than in patients with local recurrence. Moreover, TNM stage, lymphatic vessel invasion (LVI), PTEN and p-4E-BP1 might be independent risk factors for local recurrence after LARC surgery combined with concurrent radiochemotherapy.

CONCLUSIONS

This study suggests that PTEN and p-4E-BP1 might be potential biomarkers for prognostic prediction and therapeutic targets for LARC.

Circ-MALAT1 accelerates cell proliferation and epithelial mesenchymal transformation of colorectal cancer through regulating miR-506-3p/KAT6B axis

Colorectal cancer (CRC) is a prevalent malignant tumor of the digestive tract. Circular RNAs may play important roles in the progression of CRC. In this study, we investigated the roles and mechanisms of action of circ-MALAT1 in CRC. Gene expression and protein abundance were determined using qRT-PCR and western blot, respectively. Cell proliferation and migration were assessed by MTT, clone formation, and wound-healing assays. The interactions among the long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (circ-MALAT1), miR-506-3p, and lysine acetyltransferase 6B (KAT6B) were predicted using the StarBase software and confirmed by the luciferase activity assay. Circ-MALAT1 and KAT6B were upregulated, while miR-506-3p was downregulated in CRC cells. We validated that knocking down of circ-MALAT1 suppressed proliferation, migration, and epithelial-mesenchymal transition (EMT) of CRC cells, and these effects were abolished by miR-506-3p downregulation or KAT6B sufficiency. Our study suggests that circ-MALAT1 could sponge miR-506-3p to regulate the expression of KAT6B. Moreover, KAT6B sufficiency could neutralize miR-506-3p-dependent growth arrest, migration, and EMT. Circ-MALAT1 promotes cell proliferation, migration, and EMT of CRC cells via the miR-506-3p/KAT6B axis, thereby acting as a novel potential therapeutic target for the treatment of colorectal cancer.

Pathological role of long non-coding (lnc) RNA in the regulation of Wnt/β-catenin signaling pathway during epithelial-mesenchymal transition (EMT)

The term "epithelial-mesenchymal transition" (EMT) describes a biological process wherein epithelial cells acquire mesenchymal cell characteristics. This process enables the metastatic cells to migrate and invasion. Recent studies have established the connections between the EMT process and Wnt/β-catenin signaling in cancer. Key cellular functions such as differentiation, proliferation, migration, genetic stability, apoptosis, and stem cell renewal are modulated via Wnt/ β-catenin signaling pathway. Up-regulation of this evolutionarily conserved signal pathway leads to EMT. On the other hand, recent investigations have indicated that non-coding RNAs including microRNAs (miRNAs) and long non-coding RNA (lncRNAs) are involved in regulating of Wnt/β-catenin pathway. A high level of lncRNAs mainly has a positive correlation with EMT. However, lncRNA down-regulation has been observed in promoting EMT. It seems that depending on the specific targets, up-or down-regulation of lncRNAs can stimulate EMT by activating the Wnt/ β-catenin pathway. The evaluation of interactions between lncRNAs and the Wnt/ β-catenin signaling pathway in the regulation of EMT during metastasis can be fascinating. Herein, for the first time, the crucial role of lncRNAs-mediated regulation of the Wnt/ β-catenin signaling pathway in the EMT process of human tumors has been summarized.

The Role of Long Non-Coding RNAs in Epithelial-Mesenchymal Transition-Related Signaling Pathways in Prostate Cancer

Prostate cancer (PCa) is one of the most common male malignancies with frequent remote invasion and metastasis, leading to high mortality. Epithelial-mesenchymal transition (EMT) is a fundamental process in embryonic development and plays a key role in tumor proliferation, invasion and metastasis. Numerous long non-coding RNAs (lncRNAs) could regulate the occurrence and development of EMT through various complex molecular mechanisms involving multiple signaling pathways in PCa. Given the importance of EMT and lncRNAs in the progression of tumor metastasis, we recapitulate the research progress of EMT-related signaling pathways regulated by lncRNAs in PCa, including AR signaling, STAT3 signaling, Wnt/β-catenin signaling, PTEN/PI3K/AKT signaling, TGF-β/Smad and NF-κB signaling pathways. Furthermore, we summarize four modes of how lncRNAs participate in the EMT process of PCa via regulating relevant signaling pathways.

Epithelial-mesenchymal transition (EMT) in vulvar cancer with and without inguinal lymph node involvement

Purpose

Epithelial-mesenchymal transition (EMT) is associated with increased metastatic spread and poor prognosis. Data on vulvar carcinoma are limited.

Methods

Thirty-two cases of squamous cell carcinoma of the vulva (16 with and 16 without inguinal lymph node metastases) and their lymph node deposits were evaluated for immunohistochemical expression of EMT markers (vimentin, cyclin D1, e-cadherin), p16, p53 and Ki-67. Results of EMT-immunostainings were compared to lymph node involvement and expression of p53 and p16. The micro-anatomical staining pattern for EMT markers comparing the tumor center with the front of invasion was analysed in each tumor.

Results

There was no difference in the expression of EMT markers between node negative and node positive tumors. Staining for vimentin and cyclin D1 was seen within tumor cells at the front of invasion in 100 and 84.4% of the tumors, respectively. The majority of cases (68.7%) showed negative or reduced staining for e-cadherin in this micro-anatomical localization. Tumor cells within the lymph node metastases showed positive staining for e-cadherin in 75% and for cyclin D1 in 49% of the cells but were negative for vimentin in 13 out of 16 cases (81.3%). Tumors with aberrant p53 staining represented a non-significant higher vimentin but significantly higher cyclin D1 expression at the front of invasion than those with p53 wild-type pattern.

Conclusion

The present study shows no differences in the expression of EMT markers between node positive and node negative vulvar cancers. The evaluation of immunostaining within the micro-anatomical context indicates that an EMT-phenotype is restricted to the tumor cells at the front of invasion. Paired analyses of vulvar carcinomas and their lymph node deposits suggest mesenchymal-epithelial transition (MET) in the metastatic deposits. Immunohistochemical staining results may suggest that EMT is more prevalent in vulvar cancer with aberrant p53 staining.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-021-03715-2.

IMP3 protein is an independent prognostic factor of clinical stage II rectal cancer

Immunohistochemical level of IMP3-protein in patients with rectal cancer in clinical stage II (141), were correlated with sociodemographic, pathohistological and clinical indicators and duration of overall-survival and progression-free-survival. Vascular invasion was associated with IMP3-positive immunostaining (p < 0.001). Vascular invasion ratio in the group of poorly-differentiated-tumors was 21 times higher than in the group of well-differentiated-tumors. IMP3-positive patients lived 2.2 times shorter than negative (p < 0.001). Patients with well-differentiated-tumors lived 1.7 times longer than the subjects with poorly-differentiated-tumors (p < 0.001). Patients without vascular invasion lived 2.7 times longer than the subjects with vascular invasion (p < 0.001). The risk of mortality was 2.3 times higher for IMP3 positive patients (p = 0.027) and 10.4 higher for the patients with vascular invasion (p < 0.001). IMP3-negative participants had 2.3 times longer free interval without disease (p < 0.001). The free interval without disease was 3.6 times longer in the group without vascular invasion (p < 0.001). The risk of disease relapse in the IMP3 positive group was 5.3 times higher (p < 0.001) and with vascular invasion was 8 times longer (p < 0.001). The risk of disease relapse was 6.8 times higher in the group with vascular invasion (p < 0.001). Patients with rectal cancer and high IMP3-protein level will have a shorter overall survival relative to patients without or with low levels of IMP3. The analysis of IMP3 expression by immunohistochemistry pointed IMP3 as an independent prognostic factor of clinical stage II rectal cancer.

Investigation of clinicopathological characters and gene expression features in colorectal signet-ring cell carcinoma utilizing CMS classification

Signet ring cell carcinoma (SRCC) is a rare pathological type of colorectal cancer, of which the clinicopathological features and genetic background have not yet been fully investigated. Previous research has focused on the optimization of colorectal cancer treatment utilizing consensus molecular subtyping (CMS). However, it is not known what type of CMS would be designated to SRCC treatment. In the current study, of 1,350 patients diagnosed with colorectal cancer who underwent surgery, 14 were diagnosed with SRCC. The case-control cohort that fit the clinical background of the SRCC case was constructed. Statistical comparison between the SRCC group and the case-control cohort was performed among clinicopathological variables. SRCC and well to moderately adenocarcinoma case mRNA were submitted to microarray analysis and CMS analysis. Compared with the case-control cohort, the SRCC group was located more in the right-sided colon, the lymphatic invasion was more severe and the peritoneal dissemination was more frequent. The cancer-specific survival and the progression-free survival were significantly worse in the SRCC group compared with the case-control cohort. Microarray and CMS analysis identified that one SRCC case was significantly well assigned in the CMS 4 group and the other case was assigned in the CMS 1 group. Gene set analysis revealed the upregulation of EMT related genes and the downregulation of fatty acid, glycolysis, differentiation, MYC, HNF4A, DNA repair genes. In conclusion, the clinical characteristics of SRCC are severe but there is a possibility of the presence of different phenotypes according to CMS analysis.

Survival Effects of Cytoreductive Surgery for Refractory Patients after Neoadjuvant Chemotherapy in Advanced Epithelial Ovarian Cancer

PURPOSE

Salvage second-line chemotherapy is usually recommended for patients with advanced epithelial ovarian cancer (AEOC) who develop progressive disease (PD) after neoadjuvant chemotherapy (NAC). Herein, we investigated the role of cytoreductive surgery (CRS) for such patients.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 36 patients with AEOC who developed PD after receiving NAC at two tertiary academic centers with different treatment strategies between 2001 and 2016. Patients who developed PD after NAC were consistently treated with CRS at one hospital (group A; n=13) and second-line chemotherapy at another (group B; n=23). The clinical characteristics and treatment outcomes were compared between the groups.

RESULTS

Overall survival (OS) was longer in group A than in group B (19.4 months vs. 7.9 months; p=0.011). High-grade serous histology was associated with longer OS than non-high-grade serous types. In group A, optimal surgery resection (<1 cm) was achieved after CRS in 6 patients (46%). Multivariate analysis showed that the treatment option was the only independent predictive factor for OS (hazard ratio, 2.30; 95% confidence interval, 1.02-5.17; p=0.044).

CONCLUSION

CRS may result in a survival benefit even in patients with AEOC who develop PD after NAC.

The prognostic influence of tumour budding in Western patients with stage II colorectal cancer

BACKGROUND

Tumour budding (TB) refers to loss of tumour cohesiveness and is defined as isolated cells or a cell cluster of up to four tumour cells at the microscopic analysis. The International Tumour Budding Consensus Conference (ITBCC) in 2016 proposed a scoring system to standardise the pathology evaluation of TB in colorectal cancer (CRC) as high (H), intermediate (I) and low (L) TB.

OBJECTIVE

To evaluate the recurrence-free survival (RFS) of stage II CRC patients as per the ITBCC 2016 classification and associations between TB and clinical pathological features.

METHODS

Cases of stage II CRC undergoing surgery with available tumour tissue underwent central pathology review for TB. Prognostic factors, retrospectively retrieved from electronic medical charts, were evaluated in univariate and multivariate Cox regression analyses for RFS (primary end point).

RESULTS

Among 137 patients included, L-TB was observed in 107 (78.1%), I-TB in 21 (15.3%) and H-TB in 9 (6.6%). In a median follow-up of 69 months, the median RFS was 134 months, with 14 patients (10.2%) presenting with tumour recurrence: 10 (9.3%) with L-TB, 2 (9.5%) with I-TB and 2 (22.2%) with H-TB. Perineural invasion was more commonly seen in the H-TB group. In multivariate analysis, TB (H and I versus L; HR = 2.6; p = 0.059) and not receiving adjuvant chemotherapy (HR 3.7; p = 0.020) were independently associated with RFS. Adjuvant chemotherapy was associated longer RFS (HR = 3.7; p = 0.022).

CONCLUSION

In this series of Western patients, TB grade was associated with perineural invasion and increased risk of disease relapse.

HLJ2 Effectively Ameliorates Colitis-Associated Cancer via Inhibition of NF-κB and Epithelial-Mesenchymal Transition

Introduction

Colitis-associated cancer (CAC) accounts for approximately 15% of IBD patient mortalities. However, currently available anti-CAC drugs possess many disadvantages including safety, specificity and side effects. Therefore, the development of novel anti-CAC compounds is imperative. HLJ2 was a monomeric compound synthesized by our institute and reported to have an effect on ulcer colitis.

Methods

In vivo the AOM/DSS-induced CAC model was used to evaluate the effects of HLJ2 on ameliorating CAC symptoms, immunohistochemical analysis was used to analyze the pathological damage to colons and epithelial–mesenchymal transition was for changes of cytokines. In vitro, flow cytometric analysis, immunofluorescence and Western blot were used to detect the inhibition effect of HLJ2 on nuclear factor-κB and epithelial–mesenchymal transition in TGF-β1-stimulated SW480 cells.

Results

In the AOM/DSS animal model, HLJ2 was demonstrated to inhibit the secretion of inflammatory cytokines and nuclear factor-κB, levels of tumorigenesis-related proteins including snail, and finally inhibited a key step in metastasis, epithelial–mesenchymal transition. In vitro, HLJ2 was also shown to inhibit nuclear factor-κB and epithelial–mesenchymal transition in TGF-β1-stimulated SW480 cells in accordance with in vivo results. Meanwhile, the nuclear factor-κB inhibitor could interrupt the effect of HLJ2 on epithelial–mesenchymal transition.

Discussion

HLJ2 may ameliorate CAC through inhibiting nuclear factor-κB and then downstream epithelial–mesenchymal transition. The combination of the obvious improvement in effects on CAC without obvious side effects suggests that HLJ2 could be developed as a potential CAC therapeutic candidate.

Effect of preoperative chemoradiotherapy on the immunological status of rectal cancer patients

The aim of the study was to investigate the effect of chemo-radiation on the genetic and immunological status of rectal cancer patients who were treated with preoperative chemoradiotherapy (CRT). The expression of immune response-associated genes was compared between rectal cancer patients treated (n = 9) and not-treated (n = 10) with preoperative CRT using volcano plot analysis. Apoptosis and epithelial-to-mesenchymal transition (EMT) marker genes were analysed by quantitative PCR (qPCR). Other markers associated with the tumor microenvironment (TME), such as tumor-infiltrating lymphocytes (TIL) and immune checkpoint molecules, were investigated using immunohistochemistry (IHC). The clinical responses of preoperative CRT for 9 rectal cancer patients were all rated as stable disease, while the pathological tumor regression score (TRG) revealed 6 cases of grade2 and 3 cases of grade1. According to the genetic signature of colon cancers, treated tumors belonged to consensus molecular subtype (CMS)4, while not-treated tumors had signatures of CMS2 or 3. CRT-treated tumors showed significant upregulation of EMT-associated genes, such as CDH2, TGF-beta and FGF, and cancer stem cell-associated genes. Additionally, qPCR and IHC demonstrated a suppressive immunological status derived from the upregulation of inflammatory cytokines (IL-6, IL-10 and TGF-beta) and immune checkpoint genes (B7-H3 and B7-H5) and from M2-type macrophage accumulation in the tumor. The induction of EMT and immune-suppressive status in the tumor after strong CRT treatment urges the development of a novel combined therapy that restores immune-suppression and inhibits EMT, ultimately leading to distant metastasis control.

TRPM2 ion channel promotes gastric cancer migration, invasion and tumor growth through the AKT signaling pathway

Transient Receptor Potential Melastatin-2 (TRPM2) ion channel is emerging as a great therapeutic target in many types of cancer, including gastric cancer - a major health threat of cancer related-death worldwide. Our previous study demonstrated the critical role of TRPM2 in gastric cancer cells bioenergetics and survival; however, its role in gastric cancer metastasis, the major cause of patient death, remains unknown. Here, using molecular and functional assays, we demonstrate that TRPM2 downregulation significantly inhibits the migration and invasion abilities of gastric cancer cells, with a significant reversion in the expression level of metastatic markers. These effects were concomitant with decreased Akt and increased PTEN activities. Finally, TRPM2 silencing resulted in deregulation of metastatic markers and abolished the tumor growth ability of AGS gastric cancer cells in NOD/SCID mice. Taken together, our results provide compelling evidence on the important function of TRPM2 in the modulation of gastric cancer cell invasion likely through controlling the PTEN/Akt pathway.

Angiopoietin-like protein 1 inhibits epithelial to mesenchymal transition in colorectal cancer cells via suppress Slug expression

The role of ANGPTL1 in cancer development is still little known, especially in colorectal cancer (CRC). We investigated the clinical significance of ANGPTL1 expression in CRC tissues and its potential role in the progression of epithelial to mesenchymal transition (EMT) in CRC cells, which has not been reported to our knowledge. ANGPTL1 expression in CRC tissues was much lower that than in paired adjacent normal tissues by IHC, WB and qRT-PCR assays. ANGPTL1 positive expression was negatively associated with tumor size (P = 0.034), T stage (P = 0.015), lymph nodes metastasis (P = 0.045) and TNM stage (P = 0.009) and poor prognosis of CRC patients (P = 0.003). In vitro, ANGPTL1 showed decreasing expression in CRC cell lines from primary tumor to ascites metastasis. Meanwhile, ANGPTL1 silencing enhanced EMT in HCT116 cells followed with the increase of Slug, Fibronectin and Vimentin, the decrease of E-cad, and the enhancement of EMT-like cell morphology and cell invasion and migration. Low ANGPTL1 expression is closely associated with multiple clinical significance and prognosis of CRC patients. ANGPTL1 inhibits EMT of CRC cells via inhibiting E-cad suppressor Slug expression.

Mismatch repair protein expression and intratumoral budding in rectal cancer are associated with an increased pathological complete response to preoperative chemoradiotherapy: A case-control study

AIM

To determine whether the association of rectal adenocarcinoma with a defective-mismatch repair system (dMMR) was associated with a pathological complete response (pCR) to preoperative chemoradiotherapy.

METHODS

A case-control study was designed with the aim of determining if patients with rectal adenocarcinoma with dMMR had an associated high pCR rate in response to neoadjuvant chemoradiotherapy (nCRT).

RESULTS

Seventy-two cases with pCR were compared against 144 controls without pCR. Across 216 cases, the mean age was 56.8 years, 140 (64.8%) were men, and 63 (29.2%) demonstrated the dMMR system. The pCR was associated with G1 tumors, dMMR, the absence of vascular invasion, and low tumor budding in the pretreatment biopsy. In a multivariant analysis, the factors associated with pCR were dMMR (OR: 2.61; 95%CI: 1.355-5.040, P = 0.004) and a low degree of tumor budding (OR: 2.52; 95%CI: 1.366-4.894, P = 0.025).

CONCLUSION

We found an independent association between dMMR and a low rate of tumor budding, with a higher rate of pCR, in the basal biopsies of patients with rectal carcinoma subjected to nCRT.

EMT: A mechanism for escape from EGFR-targeted therapy in lung cancer

Epithelial mesenchymal transition (EMT) is a reversible developmental genetic programme of transdifferentiation of polarised epithelial cells to mesenchymal cells. In cancer, EMT is an important factor of tumour cell plasticity and has received increasing attention for its role in the resistance to conventional and targeted therapies. In this paper we provide an overview of EMT in human malignancies, and discuss contribution of EMT to the development of the resistance to Epidermal Growth Factor Receptor (EGFR)-targeted therapies in non-small cell lung cancer (NSCLC). Patients with the tumours bearing specific mutations in EGFR have a good clinical response to selective EGFR inhibitors, but the resistance inevitably develops. Several mechanisms responsible for the resistance include secondary mutations in the EGFR gene, genetic or non-mutational activation of alternative survival pathways, transdifferentiation of NSCLC to the small cell lung cancer histotype, or formation of resistant tumours with mesenchymal characteristics. Mechanistically, application of an EGFR inhibitor does not kill all cancer cells; some cells survive the exposure to a drug, and undergo genetic evolution towards resistance. Here, we present a theory that these quiescent or slow-proliferating drug-tolerant cell populations, or so-called "persisters", are generated via EMT pathways. We review the EMT-activated mechanisms of cell survival in NSCLC, which include activation of ABC transporters and EMT-associated receptor tyrosine kinase AXL, immune evasion, and epigenetic reprogramming. We propose that therapeutic inhibition of these pathways would eliminate pools of persister cells and prevent or delay cancer recurrence when applied in combination with the agents targeting EGFR.

A principled machine learning framework improves accuracy of stage II colorectal cancer prognosis

Accurate prognosis is fundamental in planning an appropriate therapy for cancer patients. Consequent to the heterogeneity of the disease, intra- and inter-pathologist variability, and the inherent limitations of current pathological reporting systems, patient outcome varies considerably within similarly staged patient cohorts. This is particularly true when classifying stage II colorectal cancer patients using the current TNM guidelines. The aim of the present work is to address this problem through the use of machine learning. In particular, we introduce a data driven framework which makes use of a large number of diverse types of features, readily collected from immunofluorescence imagery. Its outstanding performance in predicting mortality in stage II patients (AUROC = 0:94), exceeds that of current clinical guidelines such as pT stage (AUROC = 0:65), and is demonstrated on a cohort of 173 colorectal cancer patients.

The potential predictive value of tumor budding for neoadjuvant chemoradiotherapy response in locally advanced rectal cancer

Purpose

This study was conducted to investigate the potential predictive value of tumor budding for neoadjuvant chemoradiotherapy response in locally advanced rectal cancer.

Patients and methods

Surgical specimens of 128 ypUICC (Union for International Cancer Control) stage 0–III mid-to-low rectal cancer patients were identified from a prospectively maintained colorectal cancer database and classified into two groups using the 10 high-power field average method: none/mild tumor budding (BD-0) and moderate/severe tumor budding (BD-1). Overall survival, relapse-free survival (RFS), and recurrence estimates were calculated using the Kaplan–Meier method and compared with the log-rank test. For RFS, a multivariable Cox’s proportional hazards regression analysis was performed.

Results

No (n = 20) or mild (n = 27) tumor budding (BD-0) was identified in 47 (37%) and moderate (n = 52) or severe (n = 29) tumor budding (BD-1) in 81 (63%) surgical specimens. Positive tumor budding (BD-1) was associated with significantly reduced T‑level downstaging (P < 0.001) and tumor regression (P < 0.001). After a median follow-up time of 7 years (range 2.9–146.7 months), BD-0 patients had more favorable 5‑year RFS (90 vs. 71%, P = 0.02) and distant recurrence (2 vs. 12%, P = 0.03) estimates. Multivariable analyses confirmed BD-1 as a negative predictive parameter for RFS (hazard ratio = 3.44, 95% confidence interval 1.23–9.63, P = 0.018).

Conclusions

Our data confirm tumor budding as a strong prognostic factor and its potential predictive value for neoadjuvant chemoradiotherapy response in locally advanced rectal cancer patients. This provides the opportunity to modify and individualize neoadjuvant therapy regimens for non-responders.

Novel biomarkers for patient stratification in colorectal cancer: A review of definitions, emerging concepts, and data

Colorectal cancer (CRC) treatment has become more personalised, incorporating a combination of the individual patient risk assessment, gene testing, and chemotherapy with surgery for optimal care. The improvement of staging with high-resolution imaging has allowed more selective treatments, optimising survival outcomes. The next step is to identify biomarkers that can inform clinicians of expected prognosis and offer the most beneficial treatment, while reducing unnecessary morbidity for the patient. The search for biomarkers in CRC has been of significant interest, with questions remaining on their impact and applicability. The study of biomarkers can be broadly divided into metabolic, molecular, microRNA, epithelial-to-mesenchymal-transition (EMT), and imaging classes. Although numerous molecules have claimed to impact prognosis and treatment, their clinical application has been limited. Furthermore, routine testing of prognostic markers with no demonstrable influence on response to treatment is a questionable practice, as it increases cost and can adversely affect expectations of treatment. In this review we focus on recent developments and emerging biomarkers with potential utility for clinical translation in CRC. We examine and critically appraise novel imaging and molecular-based approaches; evaluate the promising array of microRNAs, analyze metabolic profiles, and highlight key findings for biomarker potential in the EMT pathway.

Newly recognized extratumoral features of colorectal cancer challenge the current tumor-node-metastasis staging system

One of the most common malignant tumors in humans, colorectal cancer has been extensively studied during the past few decades. Staging colorectal cancer allows clinicians to obtain precise prognostic information and apply specific treatment procedures. Apart from remote metastases, the depth of tumor infiltration and lymph node involvement have traditionally been recognized as the most important factors predicting outcome. Variations in the molecular signature of colorectal cancer have also revealed differences in phenotypic aggressiveness and therapeutic response rates. This article presents a review of the extratumoral environment in colorectal surgery.

Concise Review: Aggressive Colorectal Cancer: Role of Epithelial Cell Adhesion Molecule in Cancer Stem Cells and Epithelial-to-Mesenchymal Transition

Colorectal cancer (CRC) is one of the most common malignancies worldwide. In spite of various attempts to ameliorate outcome by escalating treatment, significant improvement is lacking particularly in the adjuvant setting. It has been proposed that cancer stem cells (CSCs) and the epithelial‐to‐mesenchymal transition (EMT) are at least partially responsible for therapy resistance in CRC. The epithelial cell adhesion molecule (EpCAM) was one of the first CSC antigens to be described. Furthermore, an EpCAM‐specific antibody (edrecolomab) has the merit of having launched the era of monoclonal antibody treatment in oncology in the 1990s. However, despite great initial enthusiasm, monoclonal antibody treatment has not proven successful in the adjuvant treatment of CRC patients. In the meantime, new insights into the function of EpCAM in CRC have emerged and new drugs targeting various epitopes have been developed. In this review article, we provide an update on the role of EpCAM in CSCs and EMT, and emphasize the potential predictive selection criteria for novel treatment strategies and refined clinical trial design. stemcellstranslationalmedicine2018;7:495–501

Deregulated expression of microRNA-200b/c and SUZ12, a Polycomb repressive complex 2 subunit, in chemoresistant colorectal cancer cells

In colorectal cancer, chemotherapy and/or radiotherapy can lead to the formation of resistant cells that become metastatic through Epithelial-Mesenchymal Transition (EMT). Invasive and metastatic characteristics of carcinoma cells in primary tumors are mediated by EMT. During EMT, the primary tumor cells lose cell-cell adhesion, have increased intercellular separation, and gain an elongated shape with pseudopodia. There is also dysregulation of Polycomb group proteins (such as BMI1, SUZ12, and EZH2), and changes in the expression of microRNA-200 (miR-200) family. In this study, we developed a chemoresistant colorectal cancer cell line (DLD-1-OxR) by exposing DLD-1 colorectal cancer cells to increasing concentrations of oxaliplatin (a chemotherapy drug used for colorectal cancer), and tested for EMT characteristics. We found that DLD-1-OxR exhibited EMT characteristics by morphologic, biochemical and molecular markers. SUZ12, a Polycomb repressive complex 2 subunit, was upregulated in DLD-1-OxR. The miRNA-200 family members that target SUZ12 were downregulated. Drug resistance is an impediment to chemotherapy and understanding the molecular mechanisms of chemoresistance can lead to its reversal and improvement of chemotherapy outcomes.

Diffusion kurtosis imaging evaluating epithelial-mesenchymal transition in colorectal carcinoma xenografts model: a preliminary study

Epithelial-mesenchymal transition (EMT) plays an important role in aggravating invasiveness and metastatic behavior of colorectal cancer (CRC). Identification of EMT is important for structuring treatment strategy, but has not yet been studied by using noninvasive imaging modality. Diffusion kurtosis imaging (DKI) is an advanced diffusion weighted model that could reflect tissue microstructural changes in vivo. In this study, EMT was induced in CRC cells (HCT116) by overexpressing Snail1 gene. We aimed to investigate the value of DKI in identifying EMT in CRC and decipher the correlations between DKI-derived parameters and EMT biomarker E-cadherin and cell proliferative index Ki-67 expression. Our results revealed that HCT116/Snail1 cells presented changes consistent with EMT resulting in significant increase in migration and invasion capacities. DKI could identify CRC with EMT, in which the DKI-derived parameter diffusivity was significantly lower, and kurtosis was significantly higher than those in the CRC/Control. Diffusivity was negatively and kurtosis was positively correlated with Ki-67 expression, whereas diffusivity was positively and kurtosis was negatively correlated with E-cadherin expression. Therefore, our study concluded that DKI can identify EMT in CRC xenograft tumors. EMT-contained CRC tumors with high Ki-67 and low E-cadherin expression were vulnerable to have lower diffusivity and higher kurtosis coefficients.

Expression profiling of budding cells in colorectal cancer reveals an EMT-like phenotype and molecular subtype switching

Background:

Tumour budding, described as the presence of single cells or small clusters of up to five tumour cells at the invasive margin, is established as a prognostic marker in colorectal carcinoma. In the present study, we aimed to investigate the molecular signature of tumour budding cells and the corresponding tumour bulk.

Methods:

Tumour bulk and budding areas were microdissected and processed for RNA-sequencing. As little RNA was obtained from budding cells, a special low-input mRNA library preparation protocol was used. Gene expression profiles of budding as compared with tumour bulk were investigated for established EMT signatures, consensus molecular subtype (CMS), gene set enrichment and pathway analysis.

Results:

A total of 296 genes were differentially expressed with an FDR <0.05 and a twofold change between tumour bulk and budding regions. Genes that were upregulated in the budding signature were mainly involved in cell migration and survival while downregulated genes were important for cell proliferation. Supervised clustering according to an established EMT gene signature categorised budding regions as EMT-positive, whereas tumour bulk was considered EMT-negative. Furthermore, a shift from CMS2 (epithelial) to CMS4 (mesenchymal) was observed as tumour cells transit from the tumour bulk to the budding regions.

Conclusions:

Tumour budding regions are characterised by a phenotype switch compared with the tumour bulk, involving the acquisition of migratory characteristics and a decrease in cell proliferation. In particular, most tumour budding signatures were EMT-positive and switched from an epithelial subtype (CMS2) in the tumour bulk to a mesenchymal subtype (CMS4) in budding cells.

Molecular mechanisms underlying the antitumor activity of (E)-N-hydroxy-3-(1-(4-methoxyphenylsulfonyl)-1,2,3,4-tetrahydroquinolin-6-yl)acrylamide in human colorectal cancer cells in vitro and in vivo

Upregulation of class I histone deacetylases (HDAC) correlates with poor prognosis in colorectal cancer (CRC) patients. Previous study revealed that (E)-N-hydroxy-3-(1-(4-methoxyphenylsulfonyl)-1,2,3,4-tetrahydroquinolin-6-yl)acrylamide (Compound 11) is a potent and selective class I HDAC inhibitor, exhibited significant anti-proliferative activity in various human cancer cell lines. In current study, we demonstrated that compound 11 exhibited significant anti-proliferative and cytotoxic activity in CRC cells. Notably, compound 11 was less potent than SAHA in inhibiting HDAC6 as evident from the lower expression of acetyl-α-tubulin, suggesting higher selectivity for class I HDACs. Mechanistically, compound 11 induced cell-cycle arrest at the G2/M phase, activated both intrinsic- and extrinsic-apoptotic pathways, altered the expression of Bcl-2 family proteins and exerted a potent inhibitory effect on survival signals (p-Akt, p-ERK) in CRC cells. Moreover, we provide evidence that compound 11 suppressed motility, decreased mesenchymal markers (N-cadherin and vimentin) and increased epithelial marker (E-cadherin) through down-regulation of Akt. The anti-tumor activity and underlying molecular mechanisms of compound 11 were further confirmed using the HCT116 xenograft model in vivo. Our findings provide evidence of the significant anti-tumor activity of compound 11 in a preclinical model, supporting its potential as a novel therapeutic agent for CRC.

Role of phytochemicals in the inhibition of epithelial–mesenchymal transition in cancer metastasis

Epithelial–mesenchymal transition (EMT) development is controlled by several signaling pathways including Hedgehog, Wnt, fibroblast growth factors (FGF), hepatocyte growth factor/scatter factor (HGF),etc. Phytochemicals is very promising therapeutic candidate that inhibit the progression of EMT by inhibiting the signaling pathways.

Eukaryotic translation initiation factor 5A2 (eIF5A2) regulates chemoresistance in colorectal cancer through epithelial mesenchymal transition

BACKGROUND

Chemoresistance is a major obstacle to successful chemotherapy for colorectal cancer. Eukaryotic translation initiation factor 5A2 (eIF5A2), one of the two isoforms in the eIF5A family, has been reported to be a new oncogene in many types of human cancer. In the present study, we aimed to investigate whether eIF5A2 was involved in the chemoresistance to doxorubicin in colorectal cancer.

METHODS

Cell viability was measured by CCK-8 assay with or without doxorubicin treatment. Protein expression was detected by western blot. Tumor cells were transfected with eIF5A2 siRNA or plasmid encoding eIF5A2 to down- or up regulate the expression of eIF5A2.

RESULTS

We found that eIF5A2-negtive colon cancer cells (HCT116 and HT29) were more sensitive to doxorubicin compare with the eIF5A2-positive cells (LOVO and SW480). Downregulation of eIF5A2 in LOVO and SW480 cells enhanced the chemosensitivity to doxorubicin. On the contrary, overexpression of eIF5A2 reduced doxorubicin sensitivity in colon cancer cells. In addition, eIF5A2 knockdown increased the protein level of E-cadherin and reduced vimentin expression in LOVO and SW480 cells. Meanwhile, upregulation of eIF5A2 potentiated epithelial mesenchymal transition (EMT) in colon cancer cells. Moreover, blockade of EMT with Twist siRNA abolished eIF5A2-regulated chemoresistance in colon cancer cells.

CONCLUSION

Our present study demonstrated that eIF5A2 promoted the chemoresistance to doxorubicin via regulation of EMT in colon cancer cells. Therefore, eIF5A2 inhibition may be a new potential strategy for the reversal of drug resistance in colorectal cancer therapy.

Acquisition of 5-fluorouracil resistance induces epithelial-mesenchymal transitions through the Hedgehog signaling pathway in HCT-8 colon cancer cells

Colon cancer has a high incidence in individuals >60-years-old. The commonly used chemotherapeutic agent, 5-fluorouracil (5-FU), has gradually lost its potency in treating colorectal cancer following the acquisition of resistance. Drug resistance is usually associated with epithelial-mesenchymal transitions (EMTs) in cancer cells. In the present study, the EMT phenotypes of two colon cancer cell lines, wild-type (HCT-8/WT) and 5-FU-resistant (HCT-8/5-FU), were characterized following the analysis of cellular migration, proliferation, morphology and molecular changes. In order to further clarify the mechanism of EMT in HCT-8/5-FU cells, the effect of EMT pathway inhibitors upon drug sensitivity was investigated. The results revealed that the Hedgehog signaling pathway inhibitor, GDC0449, reversed drug resistance. Therefore, inhibition of the Hedgehog pathway may provide a novel chemotherapeutic strategy for the treatment of patients with 5-FU-resistant colon cancer.

Shenling Baizhu San supresses colitis associated colorectal cancer through inhibition of epithelial-mesenchymal transition and myeloid-derived suppressor infiltration

Background

Shenling Baizhu San (SBS) is a well-known and classical Chinese medicine formula. It has been used for treatment of gastrointestinal disorders for about nine hundred years. Recent reports showed that it was effective in curing colitis and ameliorating the major manifestations of postoperational colorectal cancer (CRC). This study was to evaluate the effects of SBS on azoxymethane (AOM) and dextran sodium sulfate (DSS) induced colitis associated CRC (caCRC) and to analyze the underlying mechanism of SBS in preventing CRC.

Methods

The colon tissue of mice in different group was determined by immunohistochemistry and western blot. TGF-β1 in serum was measured by ELISA. Myeloid-derived suppressor cells (MDSCs) were identified by flow cytometry and immunohistochemistry.

Results

The formed neoplasms phenotypically resembled human caCRC with upregulated β-catenin, p53 and proliferating cell nuclear antigen (PCNA). SBS treatment reduced the death rate of mice and decreased the incidence and multiplicity of colonic neoplasms. SBS decreased the number of MDSCs and the level of transforming growth factor β1 (TGF-β1). SBS alleviated epithelial mesenchymal transition (EMT) through downregulating N-cadherin (N-cad), Vimentin, Fibronectin, Snail, and upregulating E-cadherin (E-cad). It reduced the activation of Wnt5a and EMT induced by TGF-β1.

Conclusions

SBS reduced the death rate through decreasing the incidence and multiplicity of colonic tumors. SBS lowered MDSCs infiltration and inhibited TGF-β1 induced EMT to exert its anti-caCRC effects.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-015-0649-9) contains supplementary material, which is available to authorized users.

Altered pathways and colorectal cancer prognosis

The identification of molecular markers with prognostic value in colorectal cancer is a challenging task that is needed to define therapeutic guidelines. Clinical factors are insufficient to identify those patients with stage II at risk of relapse or those patients with stage III at low risk. There is a current effort to define a consensus in molecular subtypes based on expression profiles, which are characterized by a distinctive prognostic outcome. Also several gene expression signatures based on individual genes have been proposed to predict prognosis, but they show low consistency and reproducibility. Slattery et al. describe a pathway-based approach to analyze gene expression differences between normal and colon cancer tissues. The most interesting finding is that having more deregulated pathways is associated with good prognosis. If these findings are properly validated, new insights into the mechanisms of colon carcinogenesis may be revealed. Please see related article: http://dx.doi.org/10.1186/s12916-015-0292-9 .

Implications of epithelial-mesenchymal plasticity for heterogeneity in colorectal cancer

Colorectal cancer (CRC) is a genetically heterogeneous disease that develops and progresses through several distinct pathways characterized by genomic instability. In recent years, it has emerged that inherent plasticity in some populations of CRC cells can contribute to heterogeneity in differentiation state, metastatic potential, therapeutic response, and disease relapse. Such plasticity is thought to arise through interactions between aberrant signaling events, including persistent activation of the APC/β-catenin and KRAS/BRAF/ERK pathways, and the tumor microenvironment. Here, we highlight key concepts and evidence relating to the role of epithelial–mesenchymal plasticity as a driver of CRC progression and stratification of the disease into distinct molecular and clinicopathological subsets.

Androgen-targeted therapy-induced epithelial mesenchymal plasticity and neuroendocrine transdifferentiation in prostate cancer: an opportunity for intervention

Androgens regulate biological pathways to promote proliferation, differentiation, and survival of benign and malignant prostate tissue. Androgen receptor (AR) targeted therapies exploit this dependence and are used in advanced prostate cancer to control disease progression. Contemporary treatment regimens involve sequential use of inhibitors of androgen synthesis or AR function. Although targeting the androgen axis has clear therapeutic benefit, its effectiveness is temporary, as prostate tumor cells adapt to survive and grow. The removal of androgens (androgen deprivation) has been shown to activate both epithelial-to-mesenchymal transition (EMT) and neuroendocrine transdifferentiation (NEtD) programs. EMT has established roles in promoting biological phenotypes associated with tumor progression (migration/invasion, tumor cell survival, cancer stem cell-like properties, resistance to radiation and chemotherapy) in multiple human cancer types. NEtD in prostate cancer is associated with resistance to therapy, visceral metastasis, and aggressive disease. Thus, activation of these programs via inhibition of the androgen axis provides a mechanism by which tumor cells can adapt to promote disease recurrence and progression. Brachyury, Axl, MEK, and Aurora kinase A are molecular drivers of these programs, and inhibitors are currently in clinical trials to determine therapeutic applications. Understanding tumor cell plasticity will be important in further defining the rational use of androgen-targeted therapies clinically and provides an opportunity for intervention to prolong survival of men with metastatic prostate cancer.

Pea3 expression promotes the invasive and metastatic potential of colorectal carcinoma

AIM: To investigate the function of Pea3 in colorectal carcinoma (CRC) invasion and metastatic potential.

METHODS: The expression of Pea3 during clinical progression of human CRC was investigated using Oncomine Research Edition. To assay Pea3 expression in established CRC cell lines, we performed western blotting of cell lysates. We employed shRNA-mediated knockdown of Pea3 in HCT116 (HCT) and LS174T CRC cells which was confirmed by real-time quantitative PCR (qPCR) and western blotting. Transwell invasion assays, MTS proliferation assays, anoikis assays, and fluorometric matrix metalloprotease (MMP) assays were performed to determine the effects of Pea3 knockdown on invasion, proliferation, anoikis and MMP activity in CRC cells in vitro. Alterations in epithelial-mesenchymal transition (EMT) and matrix metalloprotease (MMP) mRNA levels were determined by qPCR. CRC cells were injected into the flanks of nude mice to generate xenografts and tumor growth monitored with serial calliper measurements. To assay metastatic potential, CRC cells were injected into the spleen of nude mice, and histological analysis performed on the livers 21 d later.

RESULTS: We demonstrated that reduction of Pea3 expression in CRC cells significantly impaired their invasive capacity (HCT.shPea3, 0.28 ± 0.04 fold, P < 0.01; LS.shPea3, 0.15 ± 0.04 fold; SW.shPea3, 0.23 ± 0.03, P < 0.01), reduced anoikis resistance (HCT.shPea3 75.4% ± 1.9% viable cells vs HCT.shCtrl 88.6% ± 0.6% viable cells, P < 0.01; LS.shPea3 71.7% ± 0.5% viable cells vs LS.Ctrl 89.6% ± 0.3% viable cells, P < 0.005, but had no effect on proliferation (HCT.shCtrl AUC 5098 ± 123 vs HCT.shPea3 5689 ± 151, P < 0.05; LS.shCtrl AUC 5600 ± 324.1 vs LS.shPea3 6423 ± 400, P < 0.05). In vivo, HCT.shPea3 and HCT.shCtrl tumour xenografts grew at a similar rate (HCT.shPea3 2.64 ± 0.82 fold vs HCT.shCtrl 2.88 ± 0.80 fold, P > 0.05). In keeping with a pro-metastatic function for Pea3 in CRC, several EMT markers and MMPs were downregulated in shPea3-expressing cells, suggesting that Pea3 may exert its effects through these processes. A reduction in overall MMP activity was observed in HCT.shPea3 cells compared to their control counterparts (HCT.shPea3 0.61 ± 0.04 fold, P < 0.005). This translated in vivo to the complete absence of metastases in the livers of mice that were grafted with CRC cells lacking Pea3. Conversely, CRC cells expressing Pea3 formed liver metastases in all mice.

CONCLUSION: Our study implicates Pea3 as a mediator of metastases, and provides a biological rationale for the adverse prognosis associated with elevated Pea3 expression in human CRC.

Pien Tze Huang Overcomes Multidrug Resistance and Epithelial-Mesenchymal Transition in Human Colorectal Carcinoma Cells via Suppression of TGF-β Pathway

The traditional Chinese medicine formula Pien Tze Huang (PZH) has long been used as a folk remedy for cancer. To elucidate the mode of action of PZH against cancer, in the present study we used a 5-FU resistant human colorectal carcinoma cell line (HCT-8/5-FU) to evaluate the effects of PZH on multidrug resistance (MDR) and epithelial-mesenchymal transition (EMT) as well as the activation of TGF-β pathway. We found that PZH dose-dependently inhibited the viability of HCT-8/5-FU cells which were insensitive to treatment of 5-FU and ADM, demonstrating the ability of PZH to overcome chemoresistance. Furthermore, PZH increased the intercellular accumulation of Rhodamine-123 and downregulated the expression of ABCG2 in HCT-8/5-FU cells. In addition, drug resistance induced the process of EMT in HCT-8 cells as evidenced by EMT-related morphological changes and alteration in the expression of EMT-regulatory factors, which however was neutralized by PZH treatment. Moreover, PZH inhibited MDR/EMT-enhanced migration and invasion capabilities of HCT-8 cells in a dose-dependent manner and suppressed MDR-induced activation of TGF-β signaling in HCT-8/5-FU cells. Taken together, our study suggests that PZH can effectively overcome MDR and inhibit EMT in human colorectal carcinoma cells via suppression of the TGF-β pathway.

Knockdown of Y‑box‑binding protein‑1 inhibits the malignant progression of HT‑29 colorectal adenocarcinoma cells by reversing epithelial‑mesenchymal transition

Y‑box binding protein‑1 (YB‑1) has been identified as an oncoprotein in various malignancies. The aim of this study was to investigate the biological role of YB‑1 and its association with epithelial‑to‑mesenchymal transition (EMT) in colorectal cancer (CRC). The expression of YB‑1 and three EMT‑related proteins (E‑cadherin, N‑cadherin and vimentin) was analyzed in 80 CRC and matched normal tissue samples, by immunohistochemistry. The results indicated that the expression of YB‑1 was higher in CRC tissue samples than that in matched normal controls and was significantly correlated with tumor differentiation, tumor invasion, lymph node metastasis and distant metastases. Furthermore, analysis showed that YB‑1 expression was negatively correlated with E‑cadherin and positively correlated with N‑cadherin and vimentin expression. In vitro assays showed that knockdown of YB‑1 inhibited the proliferation, apoptosis resistance, invasion and migration of the HT‑29 CRC cell line. Of note, following knockdown of YB‑1, E‑cadherin expression was elevated whereas N‑cadherin and vimentin expression was reduced. Taken together, these results suggest that YB‑1 promotes the malignant progression of CRC in part through the induction of EMT, and YB‑1 may therefore be a potential novel target for CRC treatment.

Akt-mediated transforming growth factor-β1-induced epithelial-mesenchymal transition in cultured human esophageal squamous cancer cells

Epithelial-mesenchymal transition (EMT) has a crucial role during embryonic development and has also come under intense scrutiny as a mechanism through which esophageal squamous cell cancer (ESCC) progresses to become metastatic. Transforming growth factor beta (TGF-β)-mediated EMT has been observed in a variety of cell types and has been identified as the main inducer of EMT in many types of cancer. Akt activity is involved in TGF-β-mediated EMT; however, its precise relationship and role in EMT in ESCC has not been well explained to date. Our data demonstrated that in human ESCC tissues Akt and its activated form, phosphorylated-Akt (p-Akt), were overexpressed; in addition, Akt and p-Akt were negatively correlated with epithelial cadherin (E-cadherin). In EC-9706 cells, exogenous TGF-β1 could induce EMT and at the same time could increase the EC-9706 cell invasive and metastatic ability. Moreover, Akt knockdown by small-interfering RNA could attenuate the EMT induced by TGF-β1 by increasing the epithelial marker E-cadherin and decreasing the mesenchymal marker Vimentin. Silencing Akt expression could decrease the migration ability of EC-9706 cells efficiently. In short, Akt is likely to have a more important role in the EMT induced by TGF-β1 in EC-9706 and may contribute to the invasive and metastatic ability of EC-9706. Akt may be an effective therapeutic in advanced and metastatic ESCC.

The advantage of circulating tumor cells over serum carcinoembryonic antigen for predicting treatment responses in rectal cancer

AIM

The objective of this study was to investigate the clinical significance of circulating tumor cells (CTCs) on the evaluation and prediction of treatment responses in rectal cancer patients compared with serum carcinoembryonic antigen (CEA).

MATERIALS & METHODS

Both CTCs and CEA levels of 103 rectal cancer patients (66 with stage II-III and 37 with recurrence or metastasis) were analyzed before and after chemoradiotherapy. CTCs were detected using EpCAM magnetic bead-based enrichment combined with cytometric identification.

RESULTS

CTCs were detected in all patients while no tumor cells were found in healthy controls. CTC levels in metastatic patients were significantly higher than those with recurrence or stage II-III rectal cancer. There is a close relationship between CTC levels and treatment outcomes but serum CEA did not have any correlation.

CONCLUSION

CTCs are promising markers for the evaluation and prediction of treatment responses in rectal cancer patients, superior to the conventional tumor marker CEA.

[α-Enolase (ENO1) inhibits epithelial-mesenchymal transition in the A549 cell line by suppressing ERK1/2 phosphorylation]

背景与目的

已有的研究表明：上皮间质转换（epithelial-mesenchymal transition, EMT）是非小细胞肺癌发展和转移的一个重要过程，受到众多信号通路的精细调节。经典的丝裂原活化激酶（mitogen activated protein kinase, MAPK）信号通路是转化生长因子（transforming growth factor β, TGFβ）诱导EMT发生的必要条件。本研究以非小细胞肺癌细胞系A549为模型，对烯醇化酶（enolase-1, ENO1）影响细胞EMT过程的分子机制进行了初步研究。

方法

建立稳定过表达ENO1的A549细胞，用划痕实验检测细胞运动能力；用Western blot技术检测EMT过程相关分子标志物的变化；通过TGFβ-1诱导实验检测ENO1过表达对EMT的影响；通过上皮生长因子（epidermal growth factor, EGF）诱导实验和Western blot检测ENO1过表达引起胞外信号调节激酶（extracellular signal regulated protein kinase, ERK）磷酸化的改变。

结果

ENO1过表达抑制A549细胞侧向迁移能力。ENO1过表达还会引起上皮样标志物E-cadherin表达上调，同时间质样标志物N-cadherin和Vimentin表达下降；TGFβ-1诱导实验也证实了ENO1对EMT进程的抑制作用。EGF活化实验显示ENO1对ERK磷酸化的抑制作用。

结论

在非小细胞肺癌细胞中，ENO1具有抑制细胞EMT的作用，且很可能是通过抑制MAPK通路来实现。

The role of epithelial mesenchymal transition and resistance to neoadjuvant therapy in locally advanced rectal cancer

AIM

Nonresponse to neoadjuvant therapy is a significant challenge for clinicians managing solid cancers. This study aimed to determine whether epithelial mesenchymal transition (EMT) was associated with nonresponse to neoadjuvant therapy in patients with locally advanced rectal cancer.

METHOD

Representative tissue specimens from the tumour-invasive front of consecutive patients undergoing resection of rectal cancer from 2009 to 2011 were used. Patients with marked regression to neoadjuvant therapy were classified as responders and the remainder were classified as nonresponders. Markers of EMT included reduced immunohistochemical expression of membranous E-cadherin, increased nuclear beta-catenin expression and tumour budding. In-situ hybridization was used to assess the expression of microRNA-200c (mir200c), an upstream master-regulator of EMT.

RESULTS

Of 103 patients undergoing resection of rectal cancer, 69 received neoadjuvant chemoradiotherapy; 65% of these were nonresponders. Reduced expression of mir200c was significantly associated with a higher T grade. Reduced membranous E-cadherin, increased nuclear beta-catenin and tumour budding individually predicted the presence of extramural vascular invasion. Reduced E-cadherin, nucleic beta-catenin, reduced expression of mir200c and tumour budding were all significantly associated with nonresponse to neoadjuvant therapy (all P < 0.001). Reduced E-cadherin and expression of mir200c were both associated with reduced cancer-specific survival (log-rank P-values 0.036 and 0.009, respectively).

CONCLUSION

Targeted biomarkers of EMT were associated with nonresponse to neoadjuvant therapy and reduced survival in advanced rectal cancer. EMT may provide a practical clinical biomarker and a novel therapeutic target to improve the proportion of patients who respond to neoadjuvant therapy.

Epithelial-mesenchymal transition-like events in vulvar cancer and its relation with HPV

Background:

Epithelial-to-mesenchymal transition (EMT) still remains an obscure event in vulvar squamous cell carcinoma (VSCC).

Methods:

Immunohistochemistry (IHC) expression of E-cadherin, β-catenin, Snail, Slug, Twist and Vimentin was analysed in 87 VSCC, controlled for human papillomavirus (HPV) positivity, considering tumour front and central tumour as different morphological categories from the same tumour.

Results:

Lower β-catenin and higher Vimentin expression was associated with invasive front when compared with the central tumour (P=0.013 and P⩽0.001, respectively). Higher expression of E-cadherin in central tumour was significantly related to absence of vascular and perineural invasion, lower invasion depth and ⩽2 lymph node involvement. Loss of β-catenin and high Slug, Snail and Twist expression was associated with HPV-negative tumours. Moreover, β-catenin lower expression associated with gain in Slug expression predicts a subgroup with worst outcome (P=0.001). Lower expression of β-catenin in both central tumour and invasive front correlated with lower overall survival (P=0.021 and P=0.011, respectively). Also, multivariate analysis showed that lower β-catenin expression was independently associated with poorer outcome (P=0.044).

Conclusion:

Human papillomavirus-related tumours show better prognosis and outcome; besides, they do not progress through EMT phenomenon. Immunohistochemical analysis of β-catenin in invasive tumour front is a key issue for establishing prognosis of vulva cancer.