Colorectal Cancer Tumor Cells Research Articles

An Isoxazole Derivative SHU00238 Suppresses Colorectal Cancer Growth through miRNAs Regulation.

Colorectal cancer (CRC) is a leading cause of cancer-related deaths worldwide. Isoxazoline and isoxazole derivatives represent an important class of five-membered heterocycles, which play a pivotal role in drug discovery. In our previous study, we developed a series of isoxazole derivatives with an efficient method. In this study, we evaluated their effects on tumor cell growth. HCT116 cells were treated with isoxazole derivatives; an cholecystokinin octapeptide (CCK-8) assay was used to calculate the IC50 (half maximal inhibitory concentration) of each derivative. Compound SHU00238, which was obtained by the copper nitrate-mediated [2+2+1] cycloaddition reaction of olefinic azlactone with naphthalene-1,4-dione, has a lower IC50; we analyzed its inhibitory activity in further assays. Cell apoptosis was estimated by flow cytometry analysis in vitro. SHU00238 injection was used to treat tumor-bearing mice. We found that SHU00238 suppressed cell viability and promoted cell apoptosis in vitro. SHU00238 treatment significantly inhibited colonic tumor growth in vivo. Furthermore, we compared the miRNAs expression changes in HCT116 cells before and after SHU00238 treatment. MiRNA profiling revealed that SHU00238 treatment affected cell fate by regulating a set of miRNAs. In conclusion, SHU00238 impedes CRC tumor cell proliferation and promotes cell apoptosis by miRNAs regulation.

LncRNA-CYTOR Works as an Oncogene Through the CYTOR/miR-3679-5p/MACC1 Axis in Colorectal Cancer.

Pieces of evidence have shown that cytoskeleton regulator RNA (CYTOR), a long noncoding RNA (lncRNA), played a pivotal role in development and progression of a variety of cancers. In contrast, further research is needed to study the clinical significance and the detailed mechanism of action of lncRNA-CYTOR in colorectal cancer (CRC). This study aimed to investigate the clinical significance of CYTOR in CRC prognosis and identify the relevant potential signaling pathways and underlying mechanism of competing endogenous RNA. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) indicated that the expression of CYTOR was significantly elevated in CRC tumor tissues and cell lines. Aberrant expression of CYTOR was significantly related to TNM stage, T stage, N stage, and perineural and venous invasions. Survival analysis indicated that high-CYTOR expression was associated with poor overall survival in CRC patients (p = 0.0057), and multivariate analysis showed that high-CYTOR expression was an independent prognostic factor, which led to poor OS. In addition, bioinformatics analysis revealed that there were 18 microRNAs (miRNAs) interacted with CYTOR, and one of them, miR-3679-5p might collaborate with metastasis-associated in colon cancer-1 (MACC1), which was selected for further analysis. Pearson correlation analysis showed a significant positive correlation between the expression levels of CYTOR and MACC1. In conclusion, this study suggested that lncRNA-CYTOR played an important role in tumorigenesis and development through the CYTOR/miR-3679-5p/MACC1 axis.

Addition of immunotherapy in adjuvant setting could be a promising avenue of colorectal cancer (CRC) treatment, especially in patients with higher levels of programmed cell death ligand-1 (PD-L1) positive circulating epithelial tumor cells (CETC) after neoadjuvant chemotherapy.

e14036 Background: CRC is the third most frequent cancer in men and second in women worldwide. Recently, immune checkpoint molecules such as PD-1/PD-L1 have been identified as a possible target for immunotherapy in CRC and are increasingly being tested in clinical trials in combination with chemotherapy. However, the role of PD-L1 expression in CRC tumor cells and its interaction with other clinicopathologic factors remains elusive. In this study, we evaluated the impact of neoadjuvant chemotherapy on the fraction of PD-L1 positive CETCs and to compare its expression to the primary tumor. Methods: CETCs were determined from the blood of 20 patients suffering from CRC in different stages of the disease. The number of CETCs and their expression of PD-L1 were investigated using the maintrac method. In parallel, PD-L1 expression and tumor infiltrating lymphocytes (TILs) were assessed by immunohistochemistry on tissue biopsies. Results: PD-L1 expression could be assessed in all patients with detectable CETCs with a median of 50%. CETCs were more frequently found to be PD-L1 positive than tissue, and no correlation was observed between tissue and CETCs PD-L1 expression. Interestingly, patients with neoadjuvant chemotherapy had more positive PD-L1 CETCs compared to patients without chemotherapy (mean 66,7 vs. 35,2 p < 0.05), but the total number of CETCs was significantly lower in the neoadjuvant group. Also, patients with mucinous adenocarcinoma had more PD-L1 positive CETCs compared to other histological subtypes. The number of TILs was higher in patients with lymph node metastasis and larger tumors. TILs count did not differ in patients with and without neoadjuvant chemotherapy. Conclusions: Assessment of PD-L1 expression in CETCs is feasible, and CETCs are more often positive than in tissue. PD-L1 expression on CETCs was higher in patients who received neoadjuvant chemotherapy. Further studies are necessary to validate these findings.

Sa1692 – Clinical Potential of Circulating Tumor Cells in Colorectal Cancer: A Prospective Study

Sa1692 – Clinical Potential of Circulating Tumor Cells in Colorectal Cancer: A Prospective Study

Betulinic acid induces apoptosis and inhibits metastasis of human colorectal cancer cells in vitro and in vivo.

Betulinic acid (BA) is a pentacyclic triterpenoids extracted from birch with a wide range of biological properties. Recent studies have shown that BA has significant cytotoxicity to various types of human cancer cells, and shows potential in cancer treatment. However, the efficacy of BA on human colorectal cancer tumor cells is still unclear. The purpose of our study was to evaluate the anti-cancer activity of BA in human colorectal cancer cells in vitro and in vivo to investigate the possible mechanism. In this experiment, we found that BA inhibited colorectal cancer cell lines in vitro with a time-dependent and dose-dependent manner. Moreover, BA could induce cell apoptosis by upregulating expression of Bax and cleaved caspase-3 and downregulating protein of Bcl-2. BA could increase the production of reactive oxygen species and reduce mitochondrial membrane potential of cancer cell, suggesting that BA induced cancer cells apoptosis by mitochondrial mediated pathways. Furthermore, BA significantly inhibited the migration and invasion of colorectal cancer cells, reduced the expression of matrix metalloproteinase (MMPs) and increased the expression of MMPs inhibitor (TIMP-2). In addition, the growth of tumor was significantly suppressed by intraperitoneal administration of 20 mg/kg/day of BA in a xenograft tumor mouse model of HCT-116. Histopathological and immunohistochemical analysis showed that MMP-2+ cells and Ki-67+ cells were reduced and cleaved caspase-3+ cells were increased in tumor tissues of mice after BA administration. The results showed that BA not only promoted the apoptosis of colorectal cancer cells, but also inhibited the metastasis of cancer cells. Our results suggest that BA can be a potential natural drug to inhibit the growth and metastasis of colorectal cancer.

VSTM2A suppresses colorectal cancer and antagonizes Wnt signaling receptor LRP6.

Hyperactivation of Wnt/β-catenin signaling pathway is a critical step in colorectal tumorigenesis. In this study, we identified that V-set and transmembrane domain containing 2A (VSTM2A) was a top-downregulated secreted protein that negatively regulated Wnt singling pathways in colorectal cancer (CRC). We investigated the functional mechanisms and clinical implication of VSTM2A in CRC.Methods: Function of VSTM2A was investigated in vitro and in vivo. VSTM2A binding partner was identified by mass spectrometry, immunoprecipitation and Western blot. The clinical impact of VSTM2A was assessed in 355 CRC patients and TCGA cohort.Results: VSTM2A protein was prominently silenced in CRC tumor tissues and cell lines mediated by its promoter hypermethylation. VSTM2A DNA promoter hypermethylation and VSTM2A protein downregulation was associated with poor survival of CRC patients. Ectopic expression of VSTM2A inhibited colon cancer cell lines and organoid growth, induced CRC cells apoptosis, inhibited cell migration and invasion, and suppressed growth of xenograft tumors in nude mice. VSTM2A was released from CRC cells through a canonical secretion pathway. Secreted VSTM2A significantly suppressed Wnt signaling pathway in colon cancer cells. Wnt signaling co-receptor LDL receptor related protein 6 (LRP6) was identified as a cell membrane binding partner of VSTM2A. Using deletion/mutation and immunoprecipitation, we demonstrated that VSTM2A bound to LRP6 E1-4 domain with its IgV domain. VSTM2A suppressed LRP6 phosphorylation in a time and dose dependent manner, and induced LRP6 endocytosis and lysosome-mediated degradation, which collectively contributing to the inactivation of Wnt signaling.Conclusions: VSTM2A is a novel antagonist of canonical Wnt signaling by directly binding to LRP6 and induces LRP6 endocytosis and degradation. VSTM2A is a potential prognostic biomarker for the outcome of CRC patients.

MicroRNA-761 is downregulated in colorectal cancer and regulates tumor progression by targeting Rab3D.

The purpose of the present study was to investigate the biological role of microRNA-761 (miR-761) in colorectal cancer (CRC) and the underlying mechanisms by which miR-761 regulates CRC cell proliferation and migration. Quantitative polymerase chain reaction was performed to measure miR-761 expression in CRC tumor tissues and cell lines. It was demonstrated that miR-761 expression was dramatically reduced in CRC tumor tissues and cell lines compared with in normal tissues and cell lines. Overexpression of miR-761 significantly decreased CRC cell growth and migration. Using bioinformatics analysis and luciferase reporter assays, Rab3D was identified as a novel target of miR-761. In addition, it was demonstrated that Rab3D expression was negatively correlated with miR-761. Furthermore, overexpression of Rab3D could reverse the inhibitory effects of miR-761 on cell proliferation and migration. Collectively, the present study demonstrated that miR-761 overexpression could inhibit the proliferation and migration of CRC cell lines, partly at least, via directly targeting Rab3D.

Receptor Tyrosine Kinase EphB3: a Prognostic Indicator in Colorectal Carcinoma.

Although EphB3 expression is down-regulated in colorectal cancer (CRC) cells compared with normal intestinal epithelial cells, the relationship between EphB3 expression and clinicopathological parameters in CRC is unclear. We examined EphB3 expression in 128 CRC tissue specimens and in 19 adenoma specimens using immunohistochemistry. The relationships between EphB3 expression and clinicopathological parameters, KRAS mutations, BRAF V600E mutation, MSI and survival were evaluated using Spearman's rank correlation and Kaplan-Meier survival analyses, respectively. CpG methylation in the EphB3 promoter was examined in four human CRC cell lines and tissues. EphB3 was strongly expressed in all normal intestinal epithelial cells (128/128) and adenoma cells (19/19). In CRC tumor cells, EphB3 expression was negative or weak in 41.4% (53/128), moderate in 26.6% (34/128), and strong in 32.0% (41/128) of samples. EphB3 expression was negatively associated with invasive depth (P = 0.016, rs = -0.213), lymph node metastasis (P = 0.000, rs = -0.490), and TNM stage (P = 0.000, rs = -0.390), and was positively associated with poor differentiation (P = 0.001, rs = 0.290), BRAF V600E mutation (P= 0.008, rs= 0.235), and longer overall survival (P < 0.001). In multivariate analysis, EphB3 expression (P = 0.007) and lymph node metastasis (P < 0.001) were independent prognostic factors for poor survival. Hypermethylation of the EphB3 promoter was detected in cell lines and CRC tissues. EphB3 is down-regulated in CRC compared to normal mucosa. Hypermethylation of CpG island is contributed to downregulation of EphB3 in CRC. EphB3 expression in tumor cells may be a useful prognostic indicator for patients with CRC.

What Is the Future of Circulating Tumor Cells in Colorectal Cancer?

To introduce recent progress on circulating tumor cell (CTC) research in colorectal cancer (CRC) and to highlight clinical application of CTCs from detection to assessment of treatment response. CTC biological characteristics in CRC play an important role in the detection of CTCs. The in vitro culture of CTCs from CRC patients (cell lines and organoids) can potentially facilitate rapid drug testing and treatment prediction. CTC detection should be standardized with improved detection rate in CRC; further, clinical investigation is still needed to clarify its potential as a tool for early CRC detection, a predictive and prognostic marker to ultimately guide treatment. Gaining an improved understanding of CTCs characteristics and ultimately, integration of CTC detection and utilization of CTCs may lead to optimized tumor treatment and facilitate precision medicine.

MicroRNA-204 Inhibits the Growth and Motility of Colorectal Cancer Cells by Downregulation of CXCL8.

Among all of the miRNAs, miR-204 has gained considerable attention in the field of cancer research. This study aimed to reveal the detailed functions and the underlying mechanism of miR-204 in colorectal cancer (CRC) cells. The expressions of miR-204 in CRC tumor tissues and cell lines were monitored. Expressions of miR-204 and CXCL8 in Caco-2 and HT-29 cells were altered by transfection, and then cell viability, apoptosis, migration, invasion, EMT-related protein expression, and PI3K/AKT/mTOR pathway protein expression were assessed. We found that miR-204 was expressed at low levels in CRC tumor tissues and cell lines when compared to their normal controls. miR-204 overexpression reduced the viability, migration, and invasion of Caco-2 and HT-29 cells while significantly inducing apoptosis. miR-204 overexpression upregulated E-cadherin expression and downregulated N-cadherin and vimentin expressions. CXCL8 was a target of miR-204, and miR-204 suppression could not increase cell viability, migration, invasion, and EMT procedure when CXCL8 was silenced. Moreover, miR-204 overexpression decreased the phosphorylated levels of PI3K, AKT, and mTOR. The increased phosphorylations of PI3K, AKT, and mTOR, and the upregulation of CXCL8 induced by miR-204 suppression were all abolished by the addition of LY294002 and AZD8055 (inhibitors of PI3K/AKT and mTOR, respectively). To conclude, we demonstrated a tumor-suppressive miRNA in CRC cell lines, miR-204, which is poorly expressed in CRC tissues and cell lines. miR-204 exerted antigrowth, antimigration, anti-invasion, and anti-EMT activities, which might be via deactivating the PI3K/AKT/mTOR pathway and repressing CXCL8 expression.

Increased Levels of Oxidative Damage in Liver Metastases Compared with Corresponding Primary Colorectal Tumors: Association with Molecular Subtype and Prior Treatment

High levels of oxidative stress in disseminated colorectal cancer tumor cells may form a therapeutically exploitable vulnerability. However, it is unclear whether oxidative stress and damage persist in metastases. Therefore, we analyzed markers of oxidative damage in primary colorectal tumors and their corresponding liver metastases. Markers of generic and oxidative DNA damage [phosphorylated histone H2AX (γH2AX) and 8-hydroxy-2'-deoxyguanosine (8-OHdG)] were significantly higher in liver metastases compared with their corresponding primary tumors. Chemotherapy and/or radiotherapy before tumor resection was associated with increased persistent oxidative DNA damage, and this effect was more pronounced in metastases. Immunohistochemistry-based molecular classification into epithelial- and mesenchymal-like molecular subtypes revealed that untreated mesenchymal-like tumors contained lower levels of oxidative DNA damage compared with epithelial-like tumors. Treated mesenchymal-like tumors, but not epithelial-like tumors, showed significantly higher levels of γH2AX and 8-OHdG. Mesenchymal-like tumors expressed significantly lower levels of phosphorylated nuclear factor erythroid 2-related factor2, a master regulator of the antioxidant response, and nuclear factor erythroid 2-related factor 2-controlled genes. Of interest, a positive 8-OHdG status identified a subgroup of mesenchymal-like metastases with a poor overall survival. An increased capacity to tolerate therapy-induced oxidative damage in mesenchymal-like colorectal cancer may explain, at least in part, the poor responsiveness of these tumors to chemotherapy, which could contribute to the poor survival of this patient subgroup.

Abstract 4061: The inflammasome of tumor cells modulates the biology of tumor-infiltrating T lymphocytes in colorectal cancer

Abstract In colorectal cancer (CRC), little is known about mechanisms by which tumor cells can influence the biology of Tumor Infiltrating T lymphocytes (TILs) present in the tumor microenvironment. One of these mechanisms could be modulation of the inflammasome of tumor cells. The inflammasome is a molecular platform present in normal intestinal epithelial cells, whose effector protein, caspase-1, can rapidly mature IL-18 and generate a mucosal Th1 (IFNγ) response. However, the inflammasome status of tumor cells in CRC and its potential role in the biology of TILs are unknown yet. This prospective study aimed to determine in CRC patients (n = 50) : i) the status of the inflammasome (caspase-1 / IL-18 axis) in tumor cells according to their microsatellite status [unstable (MSI) or stable (MSS)], in relation with the density of Th1/Tc1 TILs (T-bet+) and with the levels of the prototype Th1 cytokine IFNγ, secreted in an ex vivo explant culture model of CRC we developed and ii) the impact of the inflammasome-dependent cytokines potentially secreted by tumor cells on the biology of isolated TILs. Our study delineates two major groups of patients. The first group (33% of cases, mostly MSS with a low immunoscore) featured no active caspase-1 in tumor cells, no or low levels of mature IL-18 and IFNγ and only few T-bet+ TILs in the tumor microenvironment. This profile could correspond to an immune escape mechanism facilitating tumor progression. The second group (66% of cases, both MSI and MSS with high immunoscore) featured active caspase-1 in tumor cells associated with mature IL-18 secretion, high density of T-bet+ TILs expressing IL-18Rα and IFNγ release in most cases. In addition, isolated IL-18Rα+ TILs cultured with recombinant IL-18 were able to secrete IFNγ, either left unstimulated or stimulated with anti-CD3. In these CRC, the inflammasome of tumor cells, maintained and active, can contribute to a Th1/Tc1 antitumor response elicited by TILs present in the microenvironment that can modulate tumor growth. Interestingly, in a few cases of this second group (MSI CRC), the numerous T-bet+ TILs were unable to generate a Th1 response. Noticeably, these TILs express numerous immune checkpoints including PD1 and TIGIT, potentially responsible for their exhaustion. This study is the first to delineate functional interactions between tumor cells and TILs in CRC, using ex vivo explant cultures. Altogether, our findings support the inflammasome of tumor cells as a potential new therapeutic target to strengthen the Th1/Tc1 immune response in CRC, in association with immune checkpoint blockers. This work is supported by the “Ligue contre le Cancer Grand Ouest” Citation Format: Linda Bilonda, Delphine Dansette, Cecile Deleine, Romain Oger, Nicolas Jouand, Juliette Podevin, Pierre Fourquier, Emilie Thibaudeau, Jerome Chetritt, Jean-François Mosnier, Celine Bossard, Nadine Gervois, Anne Jarry. The inflammasome of tumor cells modulates the biology of tumor-infiltrating T lymphocytes in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4061.

ATP-binding cassette member B5 (ABCB5) promotes tumor cell invasiveness in human colorectal cancer

ABC member B5 (ABCB5) mediates multidrug resistance (MDR) in diverse malignancies and confers clinically relevant 5-fluorouracil resistance to CD133-expressing cancer stem cells in human colorectal cancer (CRC). Because of its recently identified roles in normal stem cell maintenance, we hypothesized that ABCB5 might also serve MDR-independent functions in CRC. Here, in a prospective clinical study of 142 CRC patients, we found that ABCB5 mRNA transcripts previously reported not to be significantly expressed in healthy peripheral blood mononuclear cells are significantly enriched in patient peripheral blood specimens compared with non-CRC controls and correlate with CRC disease progression. In human-to-mouse CRC tumor xenotransplantation models that exhibited circulating tumor mRNA, we observed that cancer-specific ABCB5 knockdown significantly reduced detection of these transcripts, suggesting that the knockdown inhibited tumor invasiveness. Mechanistically, this effect was associated with inhibition of expression and downstream signaling of AXL receptor tyrosine kinase (AXL), a proinvasive molecule herein shown to be produced by ABCB5-positive CRC cells. Importantly, rescue of AXL expression in ABCB5-knockdown CRC tumor cells restored tumor-specific transcript detection in the peripheral blood of xenograft recipients, indicating that ABCB5 regulates CRC invasiveness, at least in part, by enhancing AXL signaling. Our results implicate ABCB5 as a critical determinant of CRC invasiveness and suggest that ABCB5 blockade might represent a strategy in CRC therapy, even independently of ABCB5's function as an MDR mediator.

Silencing of hsa_circ_0007534 suppresses proliferation and induces apoptosis in colorectal cancer cells.

Although some circRNAs have been found to regulate the progression of colorectal cancer (CRC). However, their functions have not been completely clarified. In the present study, a novel circRNA hsa_circ_0007534 was investigated in CRC tumor tissues and cell lines. The expression profile of circRNAs in CRC tumor tissues was performed by human circRNA microarray. The CCK-8 and apoptosis assay were measured in CRC cell lines after transfected with si-circRNA and si-NC. We analyzed a cohort of 33 patients with CRC and demonstrated that the expression of hsa_circ_0007534 was significantly up-regulated in CRC tumor tissues as compared to adjacent non-tumorous tissues. Moreover, hsa_circ_0007534 expression was correlated with tumor stage and lymph node metastasis. Furthermore, the silence of hsa_circ_0007534 by siRNA significantly inhibited proliferation and induced apoptosis of CRC cells. Hsa_circ_0007534 plays a crucial role in the initiation and progression of CRC and may be a potential therapeutic target of CRC.

Phosphorylation of STAT3 Promotes Vasculogenic Mimicry by Inducing Epithelial-to-Mesenchymal Transition in Colorectal Cancer.

Vasculogenic mimicry refers to the process by which highly invasive cancer cells mimic endothelial cells by forming blood channels. Vasculogenic mimicry is important for the invasion and metastasis of tumor cells in colorectal cancer. STAT3 was initially identified as a mediator of the inflammation-associated acute phase response. The phosphorylation of Signal Transducers and Activators of Transcription 3 (p-STAT3) is closely related to tumor invasion and migration. We analyzed the relationship between p-STAT3 and vasculogenic mimicry formation in 65 human colorectal cancer samples, and the results showed that the expression of p-STAT3 is significantly correlated with vasculogenic mimicry, tumor metastasis, Tumor, Lymph Node and Metastasis Stage (TNM Stage), and poor prognosis. It is known that interleukin 6 can induce the phosphorylation of STAT3. We found that using interleukin 6 to induce p-STAT3 activation in colorectal cancer cell lines can result in vasculogenic mimicry and using AG490 to suppress p-STAT3 activation restrained vasculogenic mimicry. Furthermore, the state of p-STAT3 activation can affect epithelial-to-mesenchymal transition. By immunofluorescence double staining, we discovered that p-STAT3 expression is more directly correlated with the epithelial-to-mesenchymal transition marker vimentin than with the vasculogenic mimicry-related protein VE-cadherin. These data show that activated p-STAT3 upregulates epithelial-to-mesenchymal transition–related proteins and promotes vasculogenic mimicry.

Multicolor lineage tracing reveals clonal architecture and dynamics in colon cancer

Colon cancers are composed of phenotypically heterogeneous tumor cell subpopulations with variable expression of putative stem cell and differentiation antigens. While in normal colonic mucosa, clonal repopulation occurs along differentiation gradients from crypt base toward crypt apex, the clonal architecture of colon cancer and the relevance of tumor cell subpopulations for clonal outgrowth are poorly understood. Using a multicolor lineage tracing approach in colon cancer xenografts that reflect primary colon cancer architecture, we here demonstrate that clonal outgrowth is mainly driven by tumor cells located at the leading tumor edge with clonal axis formation toward the tumor center. While our findings are compatible with lineage outgrowth in a cancer stem cell model, they suggest that in colorectal cancer tumor cell position may be more important for clonal outgrowth than tumor cell phenotype.

Prognostic value of CD133+ CD54+ CD44+ circulating tumor cells in colorectal cancer with liver metastasis.

In the previous study, we had showed the expression of CD133+ CD54+ CD44+ cellular subpopulation of circulating tumor cells (CTCs) was significantly associated with liver metastasis of colorectal cancer (CRC). This study aimed to explore whether this subpopulation of CTCs have a prognostic value in CRC patients. Flow cytometry was used to detect the expression of cellular subpopulations of CTCs with CD133, CD54, and CD44 in 152 CRC patients, between December 2013 and October 2014. The impact of clinicopathological factors and the expression of cellular subpopulations of CTCs on overall survival were then analyzed. CRC patients with liver metastases who underwent resection of the primary tumor accompanied by surgical treatment for metastasis had a better survival than other patients (P < 0.001). The liver metastatic CRC patients with high expression of CD133+ CD54+ (P < 0.001), CD133− CD54+ (P = 0.004), and CD133+ CD44+ CD54+ (P = 0.003) cellular subpopulations of CTCs had a worse survival than those patients with low expression. Multivariable survival analyses identified carcinoembryonic antigen levels (hazard ratio [HR] = 3.056; 95% confidence interval [CI] = 1.354–6.897; P = 0.007), treatment strategy (HR = 0.212; 95% CI = 0.056–0.808; P = 0.023), and CD133+ CD44+ CD54+ cellular subpopulation of CTCs (HR = 6.459; 95% CI = 1.461–28.558; P = 0.014) as independent prognostic factors for CRC patients with liver metastasis. CD133+ CD44+ CD54+ cellular subpopulation of CTCs has a prognostic value in CRC patients with liver metastasis, especially in the survival of CRC patients with liver metastasis who did not undergo surgical treatment for metastasis.

MiR-107 Promotes Proliferation and Inhibits Apoptosis of Colon Cancer Cells by Targeting Prostate Apoptosis Response-4 (Par4).

Colorectal cancer (CRC) is one of the most common malignancies in the world, with a high incidence and a high mortality. However, the pathogenesis of CRC carcinogenesis is still unexplored. In this study, we investigated the role of miR-107 in the regulation of CRC cell proliferation and apoptosis. First, the expression of miR-107 was observed to be aberrantly increased in human CRC tumor tissues and cell lines when compared to the colonic control tissues and colon epithelial cells. Further study showed that the proliferative and apoptotic capacities of human CRC SW480 and LoVo cells were aberrantly regulated by miR-107. The proliferation of SW480 and LoVo cells was remarkably enhanced by the miR-107 mimic but suppressed by the miR-107 inhibitor when compared to the negative control. On the contrary, the apoptotic rate of both SW480 and LoVo cells was significantly inhibited by miR-107 overexpression but increased by miR-107 inhibition. In addition, we identified prostate apoptosis response-4 (Par4) as a direct target of miR-107 with a potential binding site on the 3′-UTR of mRNA, as evaluated by bioinformatics prediction and luciferase reporter assay. Par4 expression levels were significantly inhibited by the miR-107 mimic but upregulated by the miR-107 inhibitor in both SW480 and LoVo cells. Compared to the control, the increase in Par4 expression significantly inhibited the induction role of miR-107 in the proliferation of SW480 and LoVo cells, and the apoptotic rate of cells repressed by the miR-107 mimic was also reversed by Par4 overexpression. In summary, our results demonstrated that miR-107 exerts a positive role in the survival of CRC cells by directly targeting Par4. This might reveal a novel understanding about human CRC pathogenesis.

High-Efficiency EpCAM/EGFR-PLGA Immunomagnetic Beads with Specific Recognition on Circulating Tumor Cells in Colorectal Cancer

High-Efficiency EpCAM/EGFR-PLGA Immunomagnetic Beads with Specific Recognition on Circulating Tumor Cells in Colorectal Cancer

Intraepithelial CD94+ tumor-infiltrating lymphocytes in a context of HLA-E overexpression as a new immune checkpoint to predict prognosis in colorectal carcinomas.

e14592 Background: A better understanding of the immune-modulating interactions between tumor cells and immune cells underlying the balance between immune control and immune resistance in colorectal cancer (CRC) is crucial for the design of immunotherapies. We have previously demonstrated that overexpression of the human MHC class Ib molecule - HLA-E/β2 microglobulin - by tumor cells in CRC was associated with an unfavorable prognosis, suggesting its involvement in immune escape. However, the specific receptor of HLA-E/β2m - CD94/NKG2A, inhibitory or CD94/NKG2C, activating - expressed by tumor-infiltrating lymphocytes (TIL), as well as the influence of the microsatellite status in HLA-E/β2m overexpression, remain unknown. Methods: We investigated in the primary tumor of 245 CRC patients 1) the association of HLA-E/β2m overexpression and the density of CD94+ intraepithelial TIL (IEL-TIL) with the microsatellite status, 2) the nature of CD94+ TIL and the receptor expressed - CD94/NKG2A or CD94/NKG2C - and 3) the prognostic influence of CD94+ IEL-TIL. Results: HLA-E/β2m was preferentially overexpressed in MSI compared with MSS CRC (44,6 % vs 18,4 % respectively, p = 0.0001), and significantly associated with a high density of CD94+ IEL-TIL in MSI (0,9% in HLA-E/β2m+ vs 0,2% in HLA-E/β2m– CRC, p = 0,001), and in MSS CRC (0,38% vs 0,15%, p &lt; 0,0001). These CD94+ TIL mostly corresponded to CD8+ αβ T cells preferentially expressing the inhibitory NKG2A chain. Finally, a high density of CD94+ IEL-TIL was independently associated with a worse OS (p = 0.03). Conclusions: These results strongly suggest that HLA-E/β2m - CD94/NKG2A interactions, preferentially up-regulated in MSI CRC, represent a promising inhibitory immune checkpoint. From a clinical point of view, this inhibitory immune checkpoint could be blocked by the new anti-NKG2A monoclonal antibody.