Cell surface markers in colorectal cancer prognosis

Cancer-Associated Fibroblast Proteins as Potential Targets against Colorectal Cancers

In colorectal cancer (CRC), attempts to identify cancer cell-specific markers to guide antibody-mediated therapeutics have failed to uncover markers that are both exclusive to cancer tissues and abundant across CRCs. Alternatively, cancer-associated fibroblasts (CAFs), which are abundant in the tumor microenvironment and upregulate unique surface markers, are not found in healthy tissues. Here, we evaluated the expression patterns of CAF-associated proteins α-smooth muscle actin (αSMA), fibroblast activation protein (FAP), podoplanin (PDPN), matrix metalloproteinase-2 (MMP2), transgelin (TAGLN), and THY1. While αSMA and THY1 were abundant in cancer tissues, high abundance in normal tissues limited their targeting potential. FAP was present in 94.5% of primary and metastatic CRC tissues and absent in 93.7% of adjacent normal colon and liver tissues assessed. These results indicate that FAP is a promising target for antibody conjugates with potential for broad application in CRC. Co-expression analyses showed that CRCs simultaneously expressing high levels of PDPN, MMP2, and THY1 were enriched for immune-related signatures, indicating potential for antibody-mediated immune engagers. Overall, this work highlights the potential of CAF proteins to act as therapeutic targets for novel anticancer agents and become important therapeutic biomarkers.

Seasonal human coronaviruses OC43, 229E, and NL63 induce cell surface modulation of entry receptors and display host cell-specific viral replication kinetics

The emergence of the COVID-19 pandemic prompted an increased interest in seasonal human coronaviruses. OC43, 229E, NL63, and HKU1 are endemic seasonal coronaviruses that cause the common cold and are associated with generally mild respiratory symptoms. In this study, we identified cell lines that exhibited cytopathic effects (CPE) upon infection by three of these coronaviruses and characterized their viral replication kinetics and the effect of infection on host surface receptor expression. We found that NL63 produced CPE in LLC-MK2 cells, while OC43 produced CPE in MRC-5, HCT-8, and WI-38 cell lines, while 229E produced CPE in MRC-5 and WI-38 by day 3 post-infection. We observed a sharp increase in nucleocapsid and spike viral RNA (vRNA) from day 3 to day 5 post-infection for all viruses; however, the abundance and the proportion of vRNA copies measured in the supernatants and cell lysates of infected cells varied considerably depending on the virus-host cell pair. Importantly, we observed modulation of coronavirus entry and attachment receptors upon infection. Infection with 229E and OC43 led to a downregulation of CD13 and GD3, respectively. In contrast, infection with NL63 and OC43 leads to an increase in ACE2 expression. Attempts to block entry of NL63 using either soluble ACE2 or anti-ACE2 monoclonal antibodies demonstrated the potential of these strategies to greatly reduce infection. Overall, our results enable a better understanding of seasonal coronaviruses infection kinetics in permissive cell lines and reveal entry receptor modulation that may have implications in facilitating co-infections with multiple coronaviruses in humans.IMPORTANCESeasonal human coronavirus is an important cause of the common cold associated with generally mild upper respiratory tract infections that can result in respiratory complications for some individuals. There are no vaccines available for these viruses, with only limited antiviral therapeutic options to treat the most severe cases. A better understanding of how these viruses interact with host cells is essential to identify new strategies to prevent infection-related complications. By analyzing viral replication kinetics in different permissive cell lines, we find that cell-dependent host factors influence how viral genes are expressed and virus particles released. We also analyzed entry receptor expression on infected cells and found that these can be up- or down-modulated depending on the infecting coronavirus. Our findings raise concerns over the possibility of infection enhancement upon co-infection by some coronaviruses, which may facilitate genetic recombination and the emergence of new variants and strains.

Protein prognostic biomarkers in stage II colorectal cancer: implications for post-operative management

Colorectal cancer (CRC) poses a significant threat to many human lives worldwide and survival following resection is predominantly stage dependent. For early-stage cancer, patients are not routinely advised to undergo additional post-operative adjuvant chemotherapy. Acceptable clinical management guidelines are well established for patients in pTNM stages I, III and IV. However, recommendations for managing CRC stage II patients remain controversial and many studies have been conducted to segregate stage II patients into low- and high-risk of recurrence using genomic, transcriptomic and proteomic molecular markers. As proteins provide valuable insights into cellular functions and disease state and have a relatively easy translation to the clinic, this review aims to discuss potential prognostic protein biomarkers proposed for predicting tumour relapse in early-stage II CRC. It is suggested that a panel of markers may be more effective than a single marker and further evaluation is required to translate these into clinical practice.

EpCAM expression negatively regulates E-cadherin function in colorectal carcinomas

Background

This study aimed to characterise epithelial cell adhesion molecule (EpCAM) expression patterns in colorectal carcinomas (CRC) from Nigerian patients, its association with E-cadherin and tumour characteristics, to forecast patient selection for anti-EpCAM therapy among whom no data existed previously.

Methods

Tissue microarray blocks of formalin-fixed and paraffin-embedded CRC tissues, with their non-cancer margins of resection, were sectioned and stained with EpCAM and E-cadherin primary antibodies. Scoring for antibody staining was done semiquantitatively by combining staining proportion and intensity. The outcome was correlated with patient age, gender and tumour histological parameters with p ≤ 0.05 regarded as statistically significant.

Results

Sixty-three carcinoma tissues had staining status for the two markers and were included in this study. Of these, 36 (57.1%) showed positive EpCAM expression (immunoscore ≥3) out of which 83% (30/36 positive cases) were overexpressed (combined immunoscore ≥4) while 12 (19%) tissues were positive for E-cadherin. Non-tumour margins of resection tissues showed less EpCAM positivity in 24% (6/25) of histospots. The difference in staining between tumour and non-tumour margin tissues with EpCAM was significant (p < 0.001). Also, EpCAM overexpression was significantly associated with reduced E-cadherin (p < 0.035) expression in tumour cells. Tumour extent within the gut wall was equal (50% each) for early and late pT stages among EpCAM overexpressing tumours but two-thirds (8/12) of cases expressing E-cadherin had later pT stage paradoxically, while distant metastasis was negligible among tumours bearing both markers. Also, tumours overexpressing EpCAM had significant association with tumour-associated lymphocytes (p < 0.02 each).

Conclusion

CRC in this study preferentially overexpress EpCAM over E-cadherin whose strong cell-cell contact inhibitory role is weakened even when expressed, resulting in further local tumour spread. This, and the observed immune response, supports targeted therapy among eligible patients.

Identification of cancer protein biomarker based on cell specific peptide and its potential role in predicting tumor metastasis

The identification of tumor related membrane protein is important for both cancer diagnosis and targeted therapy. Currently, the number of ideal clinical biomarkers is still limited partially because of lacking efficient methods in biomarker discovery. Targeting peptides are generated by library screening and can recognize their cognate targets with high specificity and affinity. In addition, these functional peptides have been considered to be a valuable molecule for both imaging detection and targeting therapy in oncology. The selected peptides can be used to identify cell-surface protein biomarkers of cancer cells. In our study, the peptide (VECYLIRDNLCIY) derived from the bacteria displaying library worked as a bait to capture its binding partner and aldolase A was identified as the candidate. The results indicated that aldolase A' expression level on the cell membrane was regulated by PI3K and aldolase A located on the membrane could inhibit the aggression of tumors through mediating cell metabolic pathway. Aldolase A could work as the joint for the metabolic and signal pathways related to tumor progression. In our work, we demonstrated a promising technology for selecting and identifying binding partners for cell-specific peptides that enables discovery of new tumor biomarkers, showing great scientific study values and clinical translation potencies. SIGNIFICANCE: MS-based cancer biomarker discovery provides promising target candidates for cancer diagnosis and therapy. However, the inevitable limits make it inconvenient in the process of sample preparation and data analysis. In this way, the small molecular probes show some advantages due to their readily availability and specific binding affinity such as the aptamers screened with SELEX technology and peptides derived from displaying libraries. In the present study, aldolase A was proved to be the membrane binding partner of a specific peptidic ligand towards ZR-75-1 tumor cell. It was discovered that membrane aldolase A was more sensitive and observable than other subcellular fractions in response to cellular metabolic state alteration or glucose availability. In addition, the reduced membrane-localized aldolase A expression indicated a more aggressive tumor phenotype and was accompanied by the upregulation of MMP-2/MMP-9. The non-glycolysis activity endowed it with potential utility as a tumor diagnostic marker and therapeutic target. This work demonstrates the practicability of screened peptide in cancer biomarker discovery, facilitating the development of diagnostic tools and therapeutic approaches to cancer, and markedly improves our understanding of cancer biology.

The SW480 cell line, overexpressing PIWIL2 gene, maintains the expression of stemness and proliferation genes in the mice xenografts

Aim

This study aims to confirm previous fundamental in vitro findings about the PIWIL2 gene by investigating the effects of its overexpression on cell cycle, proliferation, apoptosis, and stem cell expression markers in colorectal cancer cells (CRC cells) at in vivo level.

Background

PIWIL2 has a critical role in maintaining cellular stemness and proliferation. PIWIL2 is an oncogene whose expression in CRC is associated with the occurrence, metastasis, and poor prognosis.

Methods

SW480 cells harboring expression vectors with/without PIWIL2 were cultured and inoculated in BALB/c nude mice. Tumor formation and growth were monitored every 3 days. On the 28th day after inoculation, the tumors were harvested for their total RNA extraction, and the expression profiling of the candidate genes was performed by Real-time PCR.

Results

Our results for the expression profiling of the xenografted tumors showed a significant increase in the expression of cancer stem cell markers, including CD24, CD133, and pluripotency marker SOX2 in the PIWIL2 over-expressing xenografts, compared to the control cell line. Moreover, PIWIL2 dramatically promoted the anti-apoptotic pathway by inducing STAT3 and BCL2-L1 genes in the PIWIL2 over-expressing xenografts, along with the up-regulation of Cyclin D1 and Ki-67 genes.

Conclusion

This research supports our prior in vitro findings, highlighting the critical role that PIWIL2 plays in the development of CRC and its substantial promise as a leading candidate for CRC-targeted therapy.

New insight on the role of Helicobacter pylori cagA in the expression of cell surface antigens with important biological functions in gastric carcinogenesis

BACKGROUND

Expression of cluster of differentiation (CD) antigens changes according to disease status and inflammation. Profiles of CD antigens expression in gastric cancer patients are different based on the status of H. pylori infection.

AIMS

We conducted this study to profile CD antigen markers in gastric adenocarcinoma cells (AGS cell line) infected with distinct cytotoxin-associated gene A (cagA) genotypes of H. pylori clinical isolates.

METHODS

The AGS cells were infected with H. pylori isolates with different cagA genotypes, and CD antigens expression was determined using DotScan™ antibody microarray. Formation of "hummingbird" phenotype was determined, and the percentage was calculated.

RESULTS

H. pylori strains harboring cagA upregulated the expression of CD antigen involved in cancer stem cell formation (CD55), but downregulated CD antigens involved in immune regulation (CD40 and CD186) and cell adhesion (CD44). CD54 (neutrophil adhesion) and CD71 (iron transfer) were highly downregulated in the gastric cells infected with Western cagA isolates compared with East Asian isolates. CD antigen expression was different in the cells infected with H. pylori harboring different CagA EPIYA (Glu-Pro-Ile-Tyr-Ala) numbers, in which higher repression of CD54 and CD15 (Lewis x antigen) were observed in the isolate with the highest number of EPIYA motif. Furthermore, higher downregulation of CD15 was observed in the infected gastric cells with high percentage of "hummingbird" phenotype than that of low percentage of "hummingbird" phenotype.

CONCLUSION

Our study demonstrated the critical roles of CD antigens in the CagA pathogenesis and should be investigated further.

Novel Molecular classification of colorectal cancer and correlation with survival

Introduction

Colorectal cancer (CRC) is one of the most common cancers worldwide. This study was designed to evaluate biological patterns, explore molecular classification and correlate with survival outcome in treatment naïve CRC patients.

Methods

Over 11 years consecutive series of 435 CRC patients were operated on as primary surgical therapy. A total of 201 CRC patients were included, whose complete set of clinical information was available, and their good quality tumour blocks were retrieved. Immunohistochemistry was used for tumour analysis, and partitional clustering was performed using R software for cluster analysis.

Results

The median age was 43 (range 10–85) years; adenocarcinoma was the most commonly seen histological type. The great majority had positive CK20, CEA, E-Cadherin, Ki67, CDX2, and p53 expression. There were four distinct molecular classes found, whereas Ki67, CDX2, and p53 play the main role in partitioning. Younger age negatively impacted survival; overall and disease-specific survival was 26 months only with 50 months’ longest survival.

Conclusion

Colorectal cancer is a biologically heterogeneous disease with at least four distinct molecular patterns, where cell proliferation and gene repair mechanisms appear to play the key role.

Antibody Conjugated PLGA Nanocarriers and Superparmagnetic Nanoparticles for Targeted Delivery of Oxaliplatin to Cells from Colorectal Carcinoma

Anti-CD133 monoclonal antibody (Ab)-conjugated poly(lactide-co-glycolide) (PLGA) nanocarriers, for the targeted delivery of oxaliplatin (OXA) and superparamagnetic nanoparticles (IO-OA) to colorectal cancer cells (CaCo-2), were designed, synthesized, characterized, and evaluated in this study. The co-encapsulation of OXA and IO-OA was achieved in two types of polymeric carriers, namely, PLGA and poly(lactide-co-glycolide)-poly(ethylene glycol) (PLGA-PEG) by double emulsion. PLGA_IO-OA_OXA and PEGylated PLGA_IO-OA_OXA nanoparticles displayed a comparable mean diameter of 207 ± 70 nm and 185 ± 119 nm, respectively. The concentration of the released OXA from the PEGylated PLGA_IO-OA_OXA increased very rapidly, reaching ~100% release after only 2 h, while the PLGA_IO-OA_OXA displayed a slower and sustained drug release. Therefore, for a controlled OXA release, non-PEGylated PLGA nanoparticles were more convenient. Interestingly, preservation of the superparamagnetic behavior of the IO-OA, without magnetic hysteresis all along the dissolution process, was observed. The non-PEGylated nanoparticles (PLGA_OXA, PLGA_IO-OA_OXA) were selected for the anti-CD133 Ab conjugation. The affinity of Ab-coated nanoparticles for CD133-positive cells was examined using fluorescence microscopy in CaCo-2 cells, which was followed by a viability assay.

Tetraspanins: Physiology, Colorectal Cancer Development, and Nanomediated Applications

Simple Summary

Considering the high incidence of colorectal cancer in adults, as well as the need for identifying novel therapies, we hereby explore the role of tetraspanins in the development of colorectal cancer. We have focused on variate aspects starting from the structure and general physiology and ending with the precise mechanisms involved in the dual reported role of tetraspanins (pro–tumoral and tumor suppressor key player element). Moreover, the present review focuses on the potential of tetraspanins as a target for nanotechnology-mediated therapies, also gathering the limited attempts towards this aim and their reported data.

Abstract

Tetraspanins are transmembrane proteins expressed in a multitude of cells throughout the organism. They contribute to many processes that surround cell–cell interactions and are associated with the progress of some diseases, including cancer. Their crucial role in cell physiology is often understated. Furthermore, recent studies have shown their great potential in being used as targeting molecules. Data have suggested the potential of tetraspanins as a targeting vector for nanomediated distribution and delivery for colorectal cancer applications. Our aim is to provide a review on the important part that tetraspanins play in the human organism and highlight their potential use for drug delivery systems using nanotechnology.

The role of cell surface proteins gene expression in diagnosis, prognosis, and drug resistance of colorectal cancer: In silico analysis and validation

Cell surface proteins (CSPs) are an important type of protein in different essential cell functions. This study aimed to distinguish overexpressed CSPs in colorectal cancer to investigate their biomarker, prognosis, and drug resistance potential. Raw data of three datasets including 1187 samples was downloaded then normalization and differential expression were performed. By the combination of the cancer genome atlas (TCGA) clinical data, survival analysis was carried out. Information of all CSPs was collected from cell surface protein atlas. The role of each candidate gene expression was investigated in drug resistance by CCEL and GDSC data from PharmacoGX. CRC samples including 30 tumor samples and adjacent normal were used to confirm data by RT-qPCR. Outcomes showed that 66 CSPs overexpressed in three datasets, and 146 CSPs expression associated with poor prognosis features in TCGA data that TIMP1 and QSOX2 can associate with poor patient survival independently. High-risk patients illustrated more fatality than low-risk patients based on the risk score calculated by the expression level of these genes. Receiver operating characteristic curve analysis showed that 39 CSPs as perfect biomarkers for diagnosis in CRC. Furthermore, QSOX2 and TIMP1 expression levels increased in tumor samples compared to adjacent normal samples. The Drug resistance analysis demonstrated ADAM12 and COL1A2 up-regulation among 66 overexpressed CSPs caused resistance to Venetoclax and Cyclophosphamide with a high estimate, respectively. Many CSPs are deregulated in CRC, and can be valuable candidates as biomarkers for diagnosis, prognosis, and drug resistance.

Quadruple-editing of the MAPK and PI3K pathways effectively blocks the progression of KRAS-mutated colorectal cancer cells

Mutated KRAS promotes the activation of the MAPK pathway and the progression of colorectal cancer (CRC) cells. Aberrant activation of the PI3K pathway strongly attenuates the efficacy of MAPK suppression in KRAS‐mutated CRC. The development of a novel strategy targeting a dual pathway is therefore highly essential for the therapy of KRAS‐mutated CRC. In this study, a quadruple‐depleting system for the KRAS, MEK1, PIK3CA, and MTOR genes based on CRISPR/SaCas9 was developed. Adenovirus serotype 5 (ADV5) was integrated with two engineered proteins, an adaptor and a protector, to form ADV‐protein complex (APC) for systemic delivery of the CRISPR system. Quadruple‐editing could significantly inhibit the MAPK and PI3K pathways in CRC cells with oncogenic mutations of KRAS and PIK3CA or with KRAS mutation and compensated PI3K activation. Compared with MEK and PI3K/MTOR inhibitors, quadruple‐editing induced more significant survival inhibition on primary CRC cells with oncogenic mutations of KRAS and PIK3CA. The adaptor specifically targeting EpCAM and the hexon‐shielding protector could dramatically enhance ADV5 infection efficiency to CRC cells and significantly reduce off‐targeting tropisms to many organs except the colon. Moreover, quadruple‐editing intravenously delivered by APC significantly blocked the dual pathway and tumor growth of KRAS‐mutated CRC cells, without influencing normal tissues in cell‐ and patient‐derived xenograft models. Therefore, APC‐delivered quadruple‐editing of the MAPK and PI3K pathways shows a promising therapeutic potential for KRAS‐mutated CRC.

Molecular Subtyping and Outlier Detection in Human Disease Using the Paraclique Algorithm

Recent discoveries of distinct molecular subtypes have led to remarkable advances in treatment for a variety of diseases. While subtyping via unsupervised clustering has received a great deal of interest, most methods rely on basic statistical or machine learning methods. At the same time, techniques based on graph clustering, particularly clique-based strategies, have been successfully used to identify disease biomarkers and gene networks. A graph theoretical approach based on the paraclique algorithm is described that can easily be employed to identify putative disease subtypes and serve as an aid in outlier detection as well. The feasibility and potential effectiveness of this method is demonstrated on publicly available gene co-expression data derived from patient samples covering twelve different disease families.

RAD18 promotes colorectal cancer metastasis by activating the epithelial‑mesenchymal transition pathway

RAD18 is an E3 ubiquitin-protein ligase that has a role in carcinogenesis and tumor progression owing to its involvement in error-prone replication. Despite its significance, the function of RAD18 has not been fully examined in colorectal cancer (CRC). In the present research, by collecting clinical samples and conducting immunohistochemical staining, we found that RAD18 expression was significantly increased in the CRC tissue compared with that noted in the adjacent non-cancerous normal tissues and that high expression of RAD18 was associated with lymph node metastasis and poor prognosis in CRC patients. In vitro, as determined by cell transfection, scratch, and Transwell experiments, it was also demonstrated that RAD18 increased the invasiveness and migration capacity of CRC cells (HCT116, DLD-1, SW480). The signaling pathway was analyzed by western blotting and the clinical data were analyzed by immunohistochemical staining and RT-PCR, indicating that the process of epithelial-mesenchymal transition (EMT) may be involved in RAD18-mediated migration and invasion of CRC cells. All of the above data indicate that RAD18 is a novel prognostic biomarker that may become a potential therapeutic target for CRC in the future.

Computed Tomography-Based Radiomic Features Could Potentially Predict Microsatellite Instability Status in Stage II Colorectal Cancer: A Preliminary Study

RATIONALE AND OBJECTIVES

To investigate whether quantitative radiomics features extracted from computed tomography (CT) can predict microsatellite instability (MSI) status in an Asian cohort of patients with stage Ⅱ colorectal cancer (CRC).

MATERIALS AND METHODS

This retrospective study was approved by our institutional review board, and the informed consent requirement was waived. From March 2016 to March 2018, 119 Chinese patients with pathologically confirmed stage Ⅱ CRC, available MSI status, and preoperative contrast-enhanced CT images were included in this study. Clinical and pathological information was obtained from the institutional database. The radiomics features were extracted from portal venous-phase CT images of segmented volumes of each entire primary tumor by using Matrix Laboratory (MATLAB), and radiomics signatures were generated using the least absolute shrinkage and selection operator logistic regression model. The minority group was balanced via synthetic minority over-sampling technique method. The association between the clinicopathologic characteristics and MSI status was assessed using Student's t test, Chi-square, or Fisher's exact test. The predictive efficacy of MSI status using radiomics features, clinical factors (including age, gender, CT-reported tumor location, differentiation degree of tumor, smoking history, hypertension history, family history of cancer, diabetes history, level of the Ki-67 expression, and laboratory analysis) and the combined models were evaluated, respectively. Predictive performance was evaluated by the area under receiver operating characteristic curve, accuracy, sensitivity, and specificity.

RESULTS

MSI status was significantly associated with tumor location (p = 0.043); differentiation degree of tumor (p < 0.0001), hypertension history (p = 0.012), and the level of the Ki-67 expression (p = 0.015). Six radiomics features and 11 clinical characteristics were selected for predicting MSI status. The model that used the combination of clinical factors and radiomics features achieved the overall best performance than using either of the two features alone, yielding the area under the curve, sensitivity, and specificity of 0.752, 0.663, 0.841 for the combined model, 0.598, 0.371, 0.825 for clinical factors alone, and 0.688, 0.517, 0.858 for radiomics features alone, respectively.

CONCLUSION

CT-based radiomic features of stage Ⅱ CRC are associated with MSI status. Combining analysis of clinical features and CT features could improve predictive efficacy and could potentially select the patients for individualized therapy noninvasively.

Quantification and Imaging of Antigens on Cell Surface with Lipid-Encapsulated Fluorescent Nanodiamonds

Quantifying the density and locating the position of antigens on cell surface has been a challenge in molecular biology research. The challenge lies in the need for a chemically and photophysically stable fluorophore to achieve the required sensitivity and accuracy. Here, we present a method suitable for the purpose by using lipid-encapsulated fluorescent nanodiamonds (FNDs) of 35 nm in diameter as biolabels. The encapsulation of FNDs in biotinylated phospholipids not only facilitates good dispersion of the particles in biological buffers, but also endows them with high specific targeting ability. We demonstrated a viable application of the technique for biotin-mediated immunostaining of antigens on fixed human cells, identifying their positions by two-color confocal fluorescence imaging, and determining their densities by magnetically modulated fluorescence detection. A binding capacity of 6 ± 1 × 10⁴ antigens/cell was measured specifically for CD44 on HeLa cell surface. The result agreed well with the assay of R-phycoerythrin-conjugated antibodies by flow cytometry, supporting the reliability of this new nanoparticle-based method.

Up-regulation of collagen proteins in colorectal liver metastasis compared with normal liver tissue

Changes to extracellular matrix (ECM) structures are linked to tumor cell proliferation and metastasis. We previously reported that naturally occurring peptides of collagen type I are elevated in urine of patients with colorectal liver metastasis (CRLM). In the present study, we took an MS-based proteomic approach to identify specific collagen types that are up-regulated in CRLM tissues compared with healthy, adjacent liver tissues from the same patients. We found that 19 of 22 collagen-α chains are significantly up-regulated (p < 0.05) in CRLM tissues compared with the healthy tissues. At least four collagen-α chains were absent or had low expression in healthy colon and adjacent tissues, but were highly abundant in both colorectal cancer (CRC) and CRLM tissues. This expression pattern was also observed for six noncollagen colon-specific proteins, two of which (CDH17 and PPP1R1B/DARP-32) had not previously been linked to CRLM. Furthermore, we observed CRLM-associated up-regulation of 16 proteins (of 20 associated proteins identified) known to be required for collagen synthesis, indicating increased collagen production in CRLM. Immunohistochemistry validated that collagen type XII is significantly up-regulated in CRLM. The results of this study indicate that most collagen isoforms are up-regulated in CRLM compared with healthy tissues, most likely as a result of an increased collagen production in the metastatic cells. Our findings provide further insight into morphological changes in the ECM in CRLM and help explain the finding of tumor metastasis-associated proteins and peptides in urine, suggesting their utility as metastasis biomarkers.

DKK2 imparts tumor immunity evasion through β-catenin-independent suppression of cytotoxic immune-cell activation

Immunotherapy offers new options for cancer treatment, but efficacy varies across cancer types. Colorectal cancers (CRCs) are largely refractory to immune-checkpoint blockade, which suggests the presence of yet uncharacterized immune-suppressive mechanisms. Here we report that the loss of adenomatosis polyposis coli (APC) in intestinal tumor cells or of the tumor suppressor PTEN in melanoma cells upregulates the expression of Dickkopf-related protein 2 (DKK2), which, together with its receptor LRP5, provides an unconventional mechanism for tumor immune evasion. DKK2 secreted by tumor cells acts on cytotoxic lymphocytes, inhibiting STAT5 signaling by impeding STAT5 nuclear localization via LRP5, but independently of LRP6 and the Wnt-β-catenin pathway. Genetic or antibody-mediated ablation of DKK2 activates natural killer (NK) cells and CD8+ T cells in tumors, impedes tumor progression, and enhances the effects of PD-1 blockade. Thus, we have identified a previously unknown tumor immune-suppressive mechanism and immunotherapeutic targets particularly relevant for CRCs and a subset of melanomas.

A Proteomics Analysis Reveals 9 Up-Regulated Proteins Associated with Altered Cell Signaling in Colon Cancer Patients

Colorectal cancer is the second most common cancer in women and third most common cancer in men. Cell signaling alterations in colon cancer, especially in aggressive metastatic tumors, require further investigations. The present study aims to compare the expression pattern of proteins associated with cell signaling in paired tumor and non-tumor samples of patients with colon cancer, as well as to define the cluster of proteins to differentiate patients with non-metastatic (Dukes' grade B) and metastatic (Dukes' grade C&D) colon cancer. Frozen tumor and non-tumor samples were collected after tumor resection from 19 patients with colon cancer. The Panorama™ Antibody Microarray-Cell Signaling kits were used for the analyses. The expression ratios of paired tumor/non-tumor samples were calculated for the each protein. We employed R packages 'samr', 'gplots', 'supclust' (pelora, wilma algorithms), 'glmnet' for the differential expression analysis, supervised clustering and penalized logistic regression. Significance analysis of microarrays revealed 9 significantly up-regulated proteins, including protein kinase C gamma, c-Myc, MDM2, pan cytokeratin, and 1 significantly down-regulated protein (GAP1) in tumoral mucosa. Pan-cytokeratin and APP were up-regulated in tumor versus non-tumor tissue, and were selected in the predictive cluster to discriminate colon cancer type. Higher levels of S-100b and phospho-Tau-pSer199/202 were confirmed as the predictors of non-metastatic colon cancer by all employed regression/clustering methods. Deregulated proteins in colon cancer are involved in oncogenic signal transduction, cell cycle control, and regulation of cytoskeleton/transport. Further studies are needed to validate potential protein markers of colon cancer development and metastatic progression.

Inhibition of adhesion and metastasis of HepG2 hepatocellular carcinoma cells in vitro by DNA aptamer against sialyl Lewis X

The sialyl Lewis X (SLe^x) antigen encoded by the FUT7 gene is the ligand of endotheliam-selectin (E-selectin). The combination of SLe^x antigen and E-selectin represents an important way for malignant tumor metastasis. In the present study, the effect of the SLe^x-binding DNA aptamer on the adhesion and metastasis of hepatocellular carcinoma HepG2 cells in vitro was investigated. Reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence staining were conducted to detect the expression of FUT7 at both transcriptional and translational levels. The SLe^x expression in HepG2 cells treated with different concentrations of SLe^x-binding DNA aptamer was detected by flow cytometry. Besides, the adhesion, migration, and invasion of HepG2 cells were measured by cell adhesion assay, and the Transwell migration and invasion assay. The results showed that the FUT7 expression was up-regulated at both mRNA and protein levels in HepG2 cells. SLe^x-binding DNA aptamer could significantly decrease the expression of SLe^x in HepG2 cells. The cell adhesion assay revealed that the SLe^x-binding DNA aptamer could effectively inhibit the interactions between E-selectin and SLe^x in the HepG2 cells. Additionally, SLe^x-binding DNA aptamers at 20 nmol/L were found to have the similar effect to the monoclonal antibody CSLEX-1. The Transwell migration and invasion assay revealed that the number of penetrating cells on the down-side of Transwell membrane was significantly less in cells treated with 5, 10, 20 nmol/L SLe^x-binding DNA aptamer than those in the negative control group (P<0.01). Our study demonstrated that the SLe^x-binding DNA aptamer could significantly inhibit the in vitro adhesion, migration, and invasion of HepG2 cells, suggesting that the SLe^x-binding DNA aptamer may be used as a potential molecular targeted drug against metastatic hepatocellular carcinoma.

Pharmacokinetics, biodistribution and antitumour effects of Sclerotium rolfsii lectin in mice

Sclerotium rolfsii lectin (SRL) is a lectin isolated from the fungus Sclerotium rolfsii and has exquisite binding specificity towards the oncofetal Thomsen-Friedenreich antigen (TF-Ag; Galβ1-3GalNAcα-O-Ser/Thr) and its derivatives. Previous studies have shown that SRL inhibits the proliferation of human colon, breast and ovarian cancer cells in vitro and suppresses tumour growth in mice when introduced intratumourally. The present study assessed the effect of SRL on tumour growth when introduced intraperitoneally in BALB/c nude mice and investigated the pharmacokinetics and biodistribution of SRL in Swiss albino mice. When 9 doses of SRL (30 mg/kg body weight/mice) was administered to BALB/c nude mice bearing human colon cancer HT-29 xenografts, a substantial reduction in tumour size was observed. A 35.8% reduction in tumour size was noted in the treated animals after 17 days. SRL treatment also inhibited angiogenesis, and the tumours from the treated animals were observed to carry fewer blood vessels and express less angiogenesis marker protein CD31, than that from the control animals. Pharmacokinetics and biodistribution analysis revealed that SRL was detected in the serum after 1 h and its level peaked after 24 h. SRL was not detected in any of the organs apart from the kidney where a trace amount was detected after 24 h of SRL injection. No significant changes were observed in any of the biochemical parameters tested including SGOT, SGPT, LDH, CREAT and BUN in the SRL-treated mice compared to these levels in the controls. This suggests that SRL has good potential to be developed as a therapeutic agent for cancer treatment and warrant further investigations in vivo and subsequent clinical trials.

Clinical Significance and Prognostic Relevance of Microsatellite Instability in Sporadic Colorectal Cancer Patients

Microsatellite instability (MSI) is a marker of the replication error phenotype. It is caused by impaired DNA mismatch repair processes (MMR), resulting in ineffectiveness of the mechanisms responsible for the DNA replication precision and postreplicative DNA repair. MSI underlies the pathogenesis of 10%-20% of colorectal cancer (CRC) cases. The data about the potential value of MMR status as a predictive factor for 5-fluorouracil (FU)-based chemotherapy remain unclear. According to National Comprehensive Cancer Network updated guidelines, MSI testing is recommended for all patients with stage II CRC because patients with MSI-H (high-frequency MSI) tumour may have a good prognosis and obtain no benefit from 5-FU-based adjuvant chemotherapy. The significance of the MSI status as a predictive factor for patients with metastatic disease was not confirmed. The association between the MSI status and the efficacy of the therapy based on anti-programmed death-1 receptor inhibitors requires further studies.

Gold Nanoparticles in Single-Cell Analysis for Surface Enhanced Raman Scattering

The need for new therapeutic approaches in the treatment of challenging diseases such as cancer, which often consists of a highly heterogeneous and complex population of cells, brought up the idea of analyzing single cells. The development of novel techniques to analyze single cells has been intensively studied to fully understand specific alternations inducing abnormalities in cellular function. One of the techniques used for single cell analysis is surface-enhanced Raman spectroscopy (SERS) in which a noble metal nanoparticle is used to enhance Raman scattering. Due to its low toxicity and biocompatibility, gold nanoparticles (AuNPs) are commonly preferred as SERS substrates in single cell analysis. The intracellular uptake, localization and toxicity issues of AuNPs are the critical points for interpretation of data since the obtained SERS signals originate from molecules in close vicinity to AuNPs that are taken up by the cells. In this review, the AuNP-living cell interactions, cellular uptake and toxicity of AuNPs in relation to their physicochemical properties, and surface-enhanced Raman scattering from single cells are discussed.

The Architecture and Function of Monoclonal Antibody-Functionalized Mesoporous Silica Nanoparticles Loaded with Mifepristone: Repurposing Abortifacient for Cancer Metastatic Chemoprevention

The circulating tumor cells (CTCs) existing in cancer survivors are considered the root cause of cancer metastasis. To prevent the devastating metastasis cascade from initiation, we hypothesize that a biodegradable nanomaterial loaded with the abortifacient mifepristone (MIF) and conjugated with the epithelial cell adhesion molecule antibody (aEpCAM) may serve as a safe and effective cancer metastatic preventive agent by targeting CTCs and preventing their adhesion-invasion to vascular intima. It is demonstrated that MIF-loaded mesoporous silica nanoparticles (MSN) coated with aEpCAM (aE-MSN-M) can specifically target and bind colorectal cancer cells in either cell medium or blood through EpCAM recognition proven by quantitative flow cytometric detection and free aEpCAM competitive assay. The specific binding results in downregulation of the captured cells and drives them into G0/G1 phase primarily attributed to the effect of aEpCAM. The functional nanoparticles significantly inhibit the heteroadhesion between cancer cells and endothelial cells, suggesting the combined inhibition effects of aEpCAM and MIF on E-selectin and ICAM-1 expression. The functionalized nanoparticles circulate in mouse blood long enough to deliver MIF and inhibit lung metastasis. The present proof-of-concept study shows that the aE-MSN-M can prevent cancer metastasis by restraining CTC activity and their adhesion-invasion to vascular intima.

Establishment and characterization of HROC69 - a Crohn´s related colonic carcinoma cell line and its matched patient-derived xenograft

Colitis-associated colorectal cancer (CAC) seems to be a rather unique entity and differs in its genetic alterations, tumour formation capacities, and clinical features from sporadic colorectal carcinoma. Most descriptions about tumour biology of CAC refer to ulcerative colitis; data about Crohn´s colitis related carcinomas are scarce. The majority of patients with Crohn´s disease are under immunosuppression which generates a different environment for tumour growth. We first describe the clinical case of a fast growing CAC in a long-term immunosuppressed patient with Crohn´s disease and successful establishment and characterization of carcinoma cell lines along with their corresponding patient-derived xenograft. Subsequently, these tumor models were molecularly and functionally analysed. Beside numerous chromosomal alterations, mutations in TP53, APC, PTEN and SMAD3 were identified. The cell lines express numerous cancer testis antigens, surface molecules involved in immune evasion but low levels of HLA class I molecules. They show strong invasive but in comparison weak migratory activity. The present work is the first description of patient-derived in vitro and in vivo models for CAC from a Crohn´s disease patient. They might be valuable tools for analysis of genetic and epigenetic alterations, biomarker identification, functional testing, including response prediction, and the development of specific therapeutical strategies.

Cancer stem cells CD133 and CD24 in colorectal cancers in Northern Iran

AIM

We aimed to study the expression of CD24 and CD133 in colorectal cancer and normal adjacent tissues to assess a relationship between these markers and clinic-pathological characteristics and patient's survival.

BACKGROUND

Cancer stem cells are a group of tumor cells that have regeneration and multi-order differentiation capabilities.

PATIENTS AND METHODS

Expression of CD24 and CD133 was studied in a paraffin block of colorectal cancer and normal tissues near tumors with the immuneohistochemical method in patients who were referred to Imam Khomeini Hospital in Sari.

RESULTS

A total of 50 samples (25 males and 25 females) with a mean age of 67.57±13.9 years old with range 28-93 years, included 3 mucinous carcinoma and 47 adenocarcinoma. Expression of CD133 marker was negative in 29 cases and positive in 21 cases. Expression of CD24 in tissue near tumor cells was found in 30% of available samples. The relationship between expressing CD24 with treatment (surgery and chemotherapy) was significant and its relationship with patient's survival was insignificant statistically. However, there was a clear difference as mean survival age of patients based on CD24 expression was 26.64±18.15 for negative cases and 41.75±28.76 months for positive cases. CD24 and CD133 expressions and their co-expression with other clinic-pathological factors were not significant.

CONCLUSION

During this study, the relationship between CD24 and treatment type was significant. To confirm this result, various studies with high sample numbers and other stem cell markers are recommended.

Association of Wilms' tumor 1 gene single-nucleotide polymorphism rs16754 with colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality worldwide. Our recent study demonstrated that the expression of Wilms' tumor 1 gene (WT1) is associated with surgical outcome in CRC patients. The present study aimed to investigate the genetic association of the single-nucleotide polymorphism rs16754 in the WT1 gene with the occurrence of CRC, using an age-matched case-control study design. In addition, the correlation between genotype and WT1 expression was investigated. Genomic DNA samples from 104 CRC cases, aged 15-65 years, and 208 healthy controls, were genotyped for rs16754 using the TaqMan genotyping method. The genotype distribution conformed to the Hardy-Weinberg equilibrium (P=0.80). The overall minor allele frequency (MAF) of rs16754 (allele A) was 0.33. The MAF among CRC cases was significantly higher compared with that in controls (0.39 vs. 0.31, respectively; P=0.03). The AA genotype was significantly associated with the disease (odds ratio = 2.51, 95% confidence interval: 1.24-5.07, P=0.01). Cases with the AA genotype exhibited a significantly poorer 3-year overall survival (60%), compared with those with the GG or GA genotypes (80%) (log-rank test, P<0.01). Reverse transcription quantitative polymerase chain reaction analysis demonstrated that the expression of WT1 in tumor tissues was higher compared with that in normal tissue; however, there were no significant differences in its expression among different genotypes. Therefore, rs16754 was found to be associated with the occurrence and prognosis of CRC in our subjects.

Ex vivo and in vivo capture and deactivation of circulating tumor cells by dual-antibody-coated nanomaterials

Circulating tumor cells (CTCs) have been detected by us and others in cancer patient blood. However, little is known about how to specifically capture and deactivate CTCs in vivo, which may lead to successful metastasis prevention in asymptomatic cancer survivors after surgery. We hypothesize that the dual antibody conjugates may have the advantage of capturing CTCs specifically over their single antibody counterparts. Here we show that the surface-functionalized dendrimers can be sequentially coated with two antibodies directed to surface biomarkers (EpCAM and Slex) of human colorectal CTCs. The dual antibody-coated dendrimers exhibit a significantly enhanced specificity in capturing CTCs in the presence of interfering blood cells, and in both eight-patient bloods and nude mice administered with the labeled CTCs in comparison to their single antibody-coated counterparts. The dual antibody-coated conjugates down-regulate the captured CTCs. This study provides the first conceptual evidence that two antibodies can be biocompatibly conjugated to a nanomaterial to capture and down-regulate CTCs in vivo with the enhanced specificity.

Understanding the colon cancer stem cells and perspectives on treatment

An area of research that has been recently gaining attention is the relationship between cancer stem cell (CSC) biology and chemo-resistance in colon cancer patients. It is well recognized that tumor initiation, growth, invasion and metastasis are promoted by CSCs. An important reason for the widespread interest in the CSC model is that it can comprehensibly explain essential and poorly understood clinical events, such as therapy resistance, minimal residual disease, and tumor recurrence. This review discusses the recent advances in colon cancer stem cell research, the genes responsible for CSC chemoresistance, and new therapies against CSCs.

Comparative membrane proteomics: a technical advancement in the search of renal cell carcinoma biomarkers

Set-up of a specific protocol for membrane protein analysis, applied to label free, comparative proteomics of renal cell carcinoma microdomains.

The architecture and biological function of dual antibody-coated dendrimers: enhanced control of circulating tumor cells and their hetero-adhesion to endothelial cells for metastasis prevention

Dissemination of circulating tumor cells (CTCs) in blood and their hetero-adhesion to vascular endothelial bed of distant metastatic secondary organs are the critical steps to initiate cancer metastasis. The rarity of CTCs made their in vivo capture technically challenging. Current techniques by virtue of nanostructured scaffolds monovalently conjugated with a single antibody and/or drug seem less efficient and specific in capturing CTCs. Here, we report a novel platform developed to re-engineer nanoscale dendrimers for capturing CTCs in blood and interfering their adhesion to vascular endothelial bed to form micrometastatic foci. The nanoscale dendrimers were spatiotemporally accommodated with dual antibodies to target two surface biomarkers of colorectal CTCs. Physiochemical characterization, including spectra, fluorescence, electron microscope, dynamic light scattering, electrophoresis, and chromatography analyses, was conducted to demonstrate the successful conjugation of dual antibodies to dendrimer surface. The dual antibody conjugates were able to specifically recognize and bind CTCs, moderately down-regulate the activity of the captured CTCs by arresting them in S phase. The related adhesion assay displayed that the dual antibody conjugates interfered the hetero-adhesion of CTCs to fibronectin (Fn)-coated substrates and human umbilical vein endothelial cells (HUVECs). The dual antibody conjugates also showed the enhanced specificity and efficiency in vitro and in vivo in restraining CTCs in comparison with their single antibody counterparts. The present study showed a novel means to effectively prevent cancer metastatic initiation by binding, restraining CTCs and inhibiting their hetero-adhesion to blood vessels, not by traditional cytotoxic-killing of cancer cells.

Menstrual blood-derived stromal stem cells from women with and without endometriosis reveal different phenotypic and functional characteristics

Retrograde flow of menstrual blood cells during menstruation is considered as the dominant theory for the development of endometriosis. Moreover, current evidence suggests that endometrial-derived stem cells are key players in the pathogenesis of endometriosis. In particular, endometrial stromal stem cells have been suggested to be involved in the pathogenesis of this disease. Here, we aimed to use menstrual blood, as a novel source of endometrial stem cells, to investigate whether stromal stem cells from endometriosis (E-MenSCs) and non-endometriosis (NE-MenSCs) women differed regarding their morphology, CD marker expression pattern, proliferation, invasion and adhesion capacities and their ability to express certain immunomodulatory molecules. E-MenSCs were morphologically different from NE-MenSCs and showed higher expression of CD9, CD10 and CD29. Furthermore, E-MenSCs had higher proliferation and invasion potentials compared with NE-MenSCs. The amount of indoleamine 2,3-dioxygenase-1 (IDO1) and cyclooxygenase-2 (COX-2) in E-MenSCs co-cultured with allogenic peripheral blood mononuclear cells (PBMCs) was shown to be higher both at the gene and protein levels, and higher IDO1 activity was detected in the endometriosis group. However, NE-MenSCs revealed increased concentrations of forkhead transcription factor-3 (FOXP3) when compared with E-MenSCs. Nonetheless, interferon (IFN)-γ, Interleukin (IL)-10 and monocyte chemoattractant protein-1 (MCP-1) levels were higher in the supernatant of E-MenSCs-PBMC co-cultures. Here, we showed that there are inherent differences between E-MenSCs and NE-MenSCs. These findings propose the key role MenSCs could play in the pathogenesis of endometriosis and further support the retrograde and stem cell theories of endometriosis. Hence, considering its renewable and easily available nature, menstrual blood could be viewed as a reliable and inexpensive material for studies addressing the cellular and molecular aspects of endometriosis.

Role of the VDR Bsm I and Apa I polymorphisms in the risk of colorectal cancer in Kashmir

OBJECTIVE

A case-control study aiming to evaluate the relationship between Bsm I and Apa I restriction fragment gene polymorphisms and colorectal cancer (CRC) was carried out in Kashmir, including a total of 368 subjects (180 cases and 188 controls).

METHODS

DNA samples extracted from the blood of the subjects were analyzed for 3' untranslated region (3' UTR) Apa I and Bsm I polymorphisms using restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR).

RESULTS

A statistically significant 2.7-fold increased risk was observed in individuals found homozygous for the presence of the 'b' allele, in comparison to subjects homozygous for the 'B' allele (odds ratio (OR) 2.7, 95% confidence interval (CI) 1.49-4.86 (Bsm I)), and a statistically insignificant 2-fold increased risk was found among individuals with the 'aa' genotype, as compared to subjects with the 'AA' genotype (OR 2.017, 95% CI 0.86-4.7). Our study also yielded statistically significant results when the Apa I polymorphism was stratified by age (≤ 50 years) and dwelling area (rural area), and the Bsm I polymorphism by gender (male gender), suggesting a possible role of Apa I and Bsm I polymorphisms in the etiology of CRC in Kashmir.

CONCLUSION

We conclude that Apa I and Bsm I single-nucleotide polymorphisms (SNPs) in the vitamin D receptor gene (VDR) might be associated with susceptibility to CRC among Kashmiris.

Expression and clinical significance of colorectal cancer stem cell marker EpCAMhigh/CD44+ in colorectal cancer

Colorectal cancer stem cells are considered the source of recurrence, metastasis and drug resistance in colorectal tumors. Therefore, the identification and targeting of cancer stem cells facilitates the elimination of tumors. Although epithelial cell adhesion molecule-high (EpCAM^high)/cluster of differentiation (CD)44⁺ cells are thought to act as a marker of colorectal cancer stem cells, the clinical significance of these cells in colorectal cancer remains unclear. The aim of the present study was to explore the prevalence and clinical significance of colorectal cancer stem cell marker EpCAM^high/CD44⁺ in colorectal cancer. Double immunohistochemical staining was used to detect the expression of EpCAM/CD44 in 80 cases of colorectal cancer and their corresponding liver metastases. The expression of EpCAM/CD44 in colorectal cancer was analyzed, and the correlation of EpCAM^high/CD44⁺ with the biological behavior of colorectal cancer was explored. In the 80 cases of colorectal cancer studied, the presence of EpCAM^high/CD44⁺ cells had no correlation with gender, patient age or the magnitude of the tumor (P>0.05), but was significantly correlated with degree of differentiation, depth of invasion, clinical stage and metastatic status (P<0.05). In addition, EpCAM^high/CD44⁺ cells were detected in the corresponding liver metastases. Thus, the results of this study indicate that EpCAM^high/CD44⁺, a marker of colorectal cancer stem cells, is significantly correlated with the invasion and metastases of colorectal cancer.

The clinical significance of memory T cells and its subsets in gastric cancer

BACKGROUND

Long life of memory T cell (Tm) determines its crucial role in the carcinogenesis and carcinogenic progression which usually take long time. The Tm compartment contains two populations, central memory T cells (Tcm) and effector memory T cells (Tem), based on their phenotypic markers, functional attributes, and migratory properties.

METHODS

We investigated the subsets of the Tm in peripheral blood and tumor microenvironments in patients with gastric cancer by flow cytometry, and aimed to explore the correlation between the Tm and clinicopathologic features of gastric cancer.

RESULTS

The percentages of CD4(+)/CD8(+) Tm and CD4(+)/CD8(+) Tcm in peripheral blood from gastric cancer patients were statistically lower, whereas the percentages of CD4(+)/CD8(+) Tem were significantly higher than healthy controls. The proportion of CD4(+)/CD8(+) Tcm increased after tumor resection, while the percentage of the CD4(+)/CD8(+) Tem decreased significantly. Significant associations were detected between the peripheral CD4(+)/CD8(+) Tm and clinical stage, as well as the CD8(+) Tcm and clinical stage and nodal involvement. Tumor infiltrating CD8(+) Tm expressed both central and effector memory phenotypes, whereas CD4(+) Tm displayed predominantly an effector memory phenotype. Higher percentages of tumor infiltrating CD4(+)/CD8(+) Tm were significantly associated with the early disease stage.

CONCLUSIONS

Tm and its subsets were good immune indicators for the disease stage of gastric cancer. The proportion of Tm subsets may reflect the immune suppressive and immune response to the tumor associated antigen.

Combined features based on MT1-MMP expression, CD11b + immunocytes density and LNR predict clinical outcomes of gastric cancer

Background

Given the complexity of tumor microenvironment, no single marker from cancer cells could adequately predict the clinical outcomes of gastric cancer (GC). The objective of this study was to evaluate the prognostic role of combined features including conventional pathology, proteinase and immune data in GC.

Methods

In addition to pathological studies, immunohistochemistry was used to assess membrane-type 1 matrix metalloproteinase (MT1-MMP) expression and CD11b + immunocytes density in three independent GC tissue microarrays containing 184 GC tissues. Separate and combined features were evaluated for their impact on overall survival (OS).

Results

We found that traditional factors including tumor size, histological grade, lymph node status, serosa invasion and TNM stage were associated with OS (P < 0.05 for all). Moreover, statistically significant differences in OS were found among lymph node ratio (LNR) subgroups (P < 0.001), MT1-MMP subgroups (P = 0.015), and CD11b + immunocytes density subgroups (P = 0.031). Most importantly, combined feature (MT1-MMP positive, low CD11b + immunocytes density and high LNR) was found by multivariate analysis to be an independent prognostic factors for OS after excluding other confounding factors (HR = 3.818 [95%CI: 2.223-6.557], P < 0.001). In addition, this combined feature had better performance in predicting clinical outcomes after surgery long before recurrence had occurred (Area under the curve: 0.689 [95%CI: 0.609-0.768], P < 0.001).

Conclusions

These findings indicate that better information on GC prognosis could be obtained from combined clinico-pathological factors, tumor cells and the tumor microenvironment.

Functionalized magnetic nanoparticles for the detection and quantitative analysis of cell surface antigen

Cell surface antigens as biomarkers offer tremendous potential for early diagnosis, prognosis, and therapeutic response in a variety of diseases such as cancers. In this research, a simple, rapid, accurate, inexpensive, and easily available in vitro assay based on magnetic nanoparticles and magnetic cell separation principle was applied to identify and quantitatively analyze the cell surface antigen expression in the case of prostate cancer cells. Comparing the capability of the assay with flow cytometry as a gold standard method showed similar results. The results showed that the antigen-specific magnetic cell separation with antibody-coated magnetic nanoparticles has high potential for quantitative cell surface antigen detection and analysis.

Detection of circulating cancer cells using electrocatalytic gold nanoparticles

A rapid cancer cell detection and quantification assay, based on the electrocatalytic properties of gold nanoparticles towards the hydrogen evolution reaction, is described. The selective labeling of cancer cells is performed in suspension, allowing a fast interaction between the gold nanoparticle labels and the target proteins expressed at the cell membrane. The subsequent electrochemical detection is accomplished with small volumes of sample and user-friendly equipment through a simple electrochemical method that generates a fast electrochemical response used for the quantification of nanoparticle-labeled cancer cells. The system establishes a selective cell-detection assay capable of detecting 4 × 10(3) cancer cells in suspension that can be extended to several other cells detection scenarios.

Simple monitoring of cancer cells using nanoparticles

Here we present a new strategy for a simple and fast detection of cancer circulating cells (CTCs) using nanoparticles. The human colon adenocarcinoma cell line (Caco2) was chosen as a model CTC. Similarly to other adenocarcinomas, colon adenocarcinoma cells have a strong expression of EpCAM, and for this reason this glycoprotein was used as the capture target. We combine the capturing capability of anti-EpCAM functionalized magnetic beads (MBs) and the specific labeling through antibody-modified gold nanoparticles (AuNPs), with the sensitivity of the AuNPs-electrocatalyzed hydrogen evolution reaction (HER) detection technique. The fully optimized process was used for the electrochemical detection of Caco2 cells in the presence of monocytes (THP-1), other circulating cells that could interfere in real blood samples. Therefore we obtained a novel and simple in situ-like sensing format that we applied for the rapid quantification of AuNPs-labeled CTCs in the presence of other human cells.

Expression of NHERF1 in colonic tumors induced by 1,2-dimethylhydrazine in rats is independent of plasma ovarian steroids

In normal embryonic fibroblasts, the Na(+)/H(+) exchanger regulator factor 1 (NHERF1) stabilizes E-cadherin/β-catenin binding and the lack of NHERF1 expression promotes cell transformation thus acting as a tumor suppressor gene. We here tested the hypothesis that NHERF1 could act as a tumor suppressor gene in colon cancer as a mediator of estrogens' protective actions in colon carcinogenesis. We studied the expression and localization of NHERF1 and β-catenin by immunohistochemistry in colonic tumors induced by 1,2 dimethylhidrazine (DMH) in Sprague-Dawley rats. One group of the rats treated with the carcinogen was ovariectomized (OVX) in the middle of the tumor induction, simulating a human menopausal condition. We observed a protective role of estrogens in colon cancer, as non-ovariectomized rats (DMH) had a reduced tumor area compared with the ovariectomized group (DMH + OVX; mean ± SE) 28.98 ± 4.65 vs. 67.58 ± 8.69 (p < 0.00380). Despite the lack of plasma estrogen stimulation, we found abundant expression of NHERF1 in colon tumors from ovariectomized rats. NHERF1 was mainly localized in the cytoplasm of the adenocarcinoma cells and lost the apical localization previously reported in normal colon tissue. We also detected expression of NHERF1 by western blot in the SW48, CACO-2, and HT29 colon cancer cell lines. Non-estrogenic factors in plasma or the tumor microenvironment may regulate NHERF1 expression in transformed colon epithelial cells. Further studies are required to understand the regulation of NHERF1 expression in colon cancer tissue.

Predictive and prognostic factors in colorectal cancer: a personalized approach

It is an exciting time for all those engaged in the treatment of colorectal cancer. The advent of new therapies presents the opportunity for a personalized approach to the patient. This approach considers the complex genetic mechanisms involved in tumorigenesis in addition to classical clinicopathological staging. The potential predictive and prognostic biomarkers which have stemmed from the study of the genetic basis of colorectal cancer and therapeutics are discussed with a focus on mismatch repair status, KRAS, BRAF, 18qLOH, CIMP and TGF-β.