Single-cell sequencing technology in colorectal cancer: a new technology to disclose the tumor heterogeneity and target precise treatment.

Colorectal Cancer (CRC) is one of the most common gastrointestinal tumors, and its high tumor heterogeneity makes traditional sequencing methods incapable of obtaining information about the heterogeneity of individual cancer cells in CRC. Therefore, single-cell sequencing technology can be applied to better analyze the differences in genetic and protein information between cells, to obtain genomic sequence information of single cells, and to more thoroughly analyze the cellular characteristics and interactions in the CRC microenvironment. This will provide a more comprehensive understanding of colorectal cancer development and metastasis and indicate the treatment plan and prognosis. In this study, we review the application of single-cell sequencing to analyze the tumor microenvironment of CRC, explore the mechanisms involved in CRC metastasis and progression, and provide a reference for potential treatment options.

Multiregion single cell analysis reveals a novel subtype of cancer-associated fibroblasts located in the hypoxic tumor microenvironment in colorectal cancer.

BACKGROUND: The tumor microenvironment (TME) plays a critical role in shaping tumor progression and determining the outcome of the therapeutic response. In this study, we aimed to generate a comprehensive cellular landscape of the colorectal cancer (CRC) TME. METHODS: We generated a comprehensive single-cell atlas by collecting CRC cases that have been uploaded to the online database and conducting an in-depth secondary analysis. We then carried out spatial transcriptomic sequencing and multiple immunohistochemical analyses to verify the results of the single-cell analysis. Moreover, we applied our findings to the TCGA database and used tissue microarray (TMA) on CRC tissue specimens to validate clinical prognosis. FINDINGS: We re-analyzed the transcriptomes of 23785 cells, revealing a pattern of cell heterogeneity in the tumor region, leading-edge region, and non-tumor region. A subtype of COL11A1+INHBA+ tumor-resident cancer-associated fibroblasts (CAFs) was identified, and marker genes, transcription factors, and tissue-specific expression differences were noted and suggested to have potential roles in promoting cancer. We further confirmed that COL11A1+INHBA+ tumor-resident CAFs are mainly located in the hypoxic TME and we propose that they interact with CD44+ CRC cells via INHBA. Elevation of INHBA in CRC is associated with a poor prognosis. INTERPRETATION: Our results demonstrated a single cell landscape of CRC in different regions and identified in hypoxic TME a special subtype of CAFs producing INHBA, which promotes CRC development and correlates with poor prognosis. This special subtype of CAFs is a candidate target for translational research.

High expression of phosphorylated focal adhesion kinase predicts a poor prognosis in human colorectal cancer.

Background: Phosphorylated Focal adhesion kinase (FAK) has been reported to be intimately involved in various malignant tumors. The effect of p-FAK on colorectal cancer (CRC) is still disputable. The purpose of this study is to investigate the role of p-FAK in the prognosis of colorectal cancer. Methods: The clinical significance of p-FAK expression in CRC was evaluated by immunohistochemistry in a large cohort, including carcinoma and para-carcinoma tissues from 908 patients, and normal tissues, adenoma, and metastasis tissues. The correlation between p-FAK expression and CRC occurrence was investigated in tumor and other tissues. Factors contributing to prognosis were evaluated using Kaplan-Meier survival analysis and Cox regression model. Results: p-FAK is apparently overexpressed in CRC and metastasis tissues. Compared with low p-FAK expression, patients with high p-FAK expression had shorter overall survival [hazard ratio (HR), 2.200; 95% confidence interval (CI), 1.265-3.452; p < 0.01] and disease-free survival (HR, 2.004; 95% CI 1.262-3.382; p < 0.01) in multivariate Cox analysis after adjusting other prognostic factors. High p-FAK expression was also related to a worse chemotherapeutic response in patients who achieved adjuvant chemotherapy (p < 0.01). Conclusion: Expression level of p-FAK is an independent risk factor and can serve as a prognostic biomarker for CRC. High p-FAK expression predicts an unfavorable prognosis of CRC as well as poor chemotherapeutic response.

Therapeutic Suppression of FAK-AKT Signaling Overcomes Resistance to SHP2 Inhibition in Colorectal Carcinoma.

SHP2 mediates signaling from multiple receptor tyrosine kinases (RTKs) to extracellular signal-regulated kinase (ERK) and Ser and Thr kinase AKT, and its inhibitors offer an unprecedented opportunity for cancer treatment. Although the ERK signaling variation after SHP2 inhibition has been well investigated, the AKT signaling variation in colorectal carcinoma (CRC) is still unknown. Therefore, we performed immunohistochemistry and bioinformatics analyses to explore the significance of p-SHP2 in CRC. A panel of CRC cell lines with the SHP2 inhibitor, SHP099, was used to assess the effects on viability and signaling. The inhibitors of AKT and focal adhesion kinase (FAK) signaling were examined in combination with SHP099 as potential strategies to enhance the efficacy and overcome resistance. Frequent resistance to the SHP2 inhibitor was observed in CRC cells, even in those without RAS mutations. We observed rapid adaptive reactivation of the AKT pathway in response to SHP2 inhibition, possibly driven by the reactivation of RTKs or released p-FAK. High baseline p-FAK may also be associated with CRC cell resistance to SHP2 inhibition. Co-inhibition of FAK abrogated the feedback reactivation of AKT in response to SHP2 inhibition. Moreover, the combined inhibition of SHP2 with AKT or FAK resulted in sustained AKT pathway suppression and improved antitumor efficacy in vitro and in vivo. Our study found that reactivation of the AKT pathway is a key mechanism of adaptive resistance to SHP2 inhibition, highlighting the potential significance of AKT and FAK inhibition strategies to enhance the efficacy of SHP2 inhibitors in CRC treatment.

Effective Predictor of Colorectal Cancer Survival Based on Exclusive Expression Pattern Among Different Immune Cell Infiltration.

Tumor-infiltrating immune/inflammatory cells, the important components of the tumor microenvironment (TME), remarkably affect the progression of human cancers. To understand the actual conditions within the TME of colorectal cancer (CRC), the interrelationship among tumor-infiltrating neutrophils, M2 macrophages, and regulatory T-cells (Tregs) was systematically analyzed. The infiltration conditions of CD66b+ neutrophils, CD163+ M2 macrophages, and FOXP3+ Tregs in tissue microarrays including 1021 cases of CRC were determined by immunohistochemical analysis. The prediction power of these immune cells for CRC prognosis was evaluated by subgroup analysis of the CRC cohort. Results revealed the existence pattern of infiltrating neutrophils, and Tregs/M2 macrophages fulfilled a "X-low implies Y-high" Boolean relationship, indicative of a mutually exclusive correlation between neutrophils and M2 macrophages, and between neutrophils and Tregs in the TME of CRC. What's more, the tumor-infiltrating M2 macrophages and Tregs were associated with adverse prognostic factors, whereas neutrophils were corelated with favorable factors. The high infiltration of neutrophils predicted longer survival and better chemotherapeutic response. Nonetheless, high infiltration of M2 macrophages and Tregs predicted poor prognosis. The combination of these tumor-infiltrating immune cells can serve as an effective predictor for the survival of CRC and for the chemotherapeutic outcomes of stage II-III patients. .

Discovery and validation of methylation signatures in blood-based circulating tumor cell-free DNA in early detection of colorectal carcinoma: a case-control study.

BACKGROUND: Early detection of colorectal carcinoma (CRC) would help to identify tumors when curative treatments are available and beneficial. However, current screening methods for CRC, e.g., colonoscopy, may affect patients' compliance due to the uncomfortable, invasive and time-consuming process. In recent decades, methylation profiles of blood-based circulating tumor DNA (ctDNA) have shown promising results in the early detection of multiple tumors. Here we conducted a study to investigate the performance of ctDNA methylation markers in early detection of CRC. RESULTS: In total, 742 participants were enrolled in the study including CRC (n = 332), healthy control (n = 333), benign colorectal disease (n = 65) and advanced adenoma (n = 12). After age-matched and randomization, 298 participants (149 cancer and 149 healthy control) were included in training set and 141 (67 cancer and 74 healthy control) were in test set. In the training set, the specificity was 89.3% (83.2-93.7%) and the sensitivity was 88.6% (82.4-93.2%). In terms of different stages, the sensitivities were 79.4% (62.1-91.2%) in patients with stage I, 88.9% (77.3-95.8%) in patients with stage II, 91.4% (76.9-98.2%) in patients with stage III and 96.2% (80.3-99.9%) in patients with stage IV. Similar results were validated in the test set with the specificity of 91.9% (83.1-97.0%) and sensitivity of 83.6% (72.5-91.6%). Sensitivities for stage I-III were 87.0% (79.7-92.4%) in the training set and 82.5% (70.2-91.3%) in the test set, respectively. In the unmatched total population, the positive ratios were 7.8% (5.2-11.2%) in healthy control, 30.8% (19.9-43.5%) in benign colorectal disease and 58.3% (27.5-84.7%) in advanced adenoma, while the sensitivities of stage I-IV were similar with training and test sets. Compared with methylated SEPT9 model, the present model had higher sensitivity (87.0% [81.8-91.2%] versus 41.2% [34.6-48.1%], P < 0.001) under comparable specificity (90.1% [85.4-93.7%] versus 90.6% [86.0-94.1%]). CONCLUSIONS: Together our findings showed that ctDNA methylation markers were promising in the early detection of CRC. Further validation of this model is warranted in prospective studies.

High expression of SH2B adaptor protein 1 (SH2B1) indicates poor prognosis in colorectal cancer.

SH2B1, an adaptor protein associated with obesity, is closely related to the occurrence and development of a variety of tumors. To investigate the clinical significance of SH2B1 in colorectal cancer (CRC), expression of SH2B1 in colorectal normal tissues, adenomas, paracarcinoma tissues, carcinoma tissues, and metastatic tissues from 1003 CRC patients was detected by immunohistochemistry (IHC). The prediction power of SH2B1 for CRC prognosis was evaluated by Kaplan-Meier survival analysis and Cox regression model. Results revealed the expression of SH2B1 in carcinoma tissues was significantly higher than that in other tissues. High expression of SH2B1 was an independent risk factor for both disease-free survival (DFS) and disease-specific survival (DSS) and predicted unfavorable prognosis of CRC as well as poor chemotherapeutic response. Conclusively, SH2B1 can serve as an effective predictor for CRC survival and chemotherapeutic outcomes.

High stromal nicotinamide N-methyltransferase (NNMT) indicates poor prognosis in colorectal cancer.

PURPOSE: Nicotinamide n-methyltransferase (NNMT) has good biochemical activity and epigenetic regulation, and has been reported as a major metabolic regulator of cancer. The goal of this study was to investigate the significance of stromal NNMT expression in colorectal cancer (CRC). PATIENTS AND METHODS: Stromal expression of NNMT in primary CRC, metastasis CRC, and their non-cancerous tissues from 1088 CRC patients was examined by immunohistochemistry. The associations between stromal NNMT expression and survival outcomes in 967 patients with stage I-III CRC were further evaluated with Kaplan-Meier curve and Cox model analyses. RESULTS: NNMT expression was mainly sourced from stromal compartments and also elevated in CRC. Patients with high stromal NNMT (IHC-score ≥ 106) have a worse survival than those patients with low stromal NNMT. In multiple Cox analyses, high expression of stromal NNMT remained as an independent risk factor in CRC for disease-free survival with a hazard ratio (HR) of 1.415 (95% confidence interval [CI], 1.015-1.972) and disease-specific survival with a HR of 5.004 (95% CI, 2.301-10.883). In addition, high stromal NNMT expression in CRC also indicates the poor survival outcomes in patients with early stage CRC (stage I and II) and in patients who undergo chemotherapy. CONCLUSION: NNMT is mainly located in CRC stromal compartment. High stromal NNMT expression predicts an unfavorable postoperative prognosis.

MicroRNA-142-3p Inhibits Tumorigenesis of Colorectal Cancer via Suppressing the Activation of Wnt Signaling by Directly Targeting to ß-Catenin.

BACKGROUND: Altered expression profile of microRNAs (miRNAs) was reported to be associated with colorectal cancer (CRC). The aims of this study are to identify the changed miRNAs in the plasma of CRC patients and explore the underlying mechanism of these miRNAs during tumorigenesis. METHODS: Plasma miRNA expression profiles were compared between healthy people and CRC patients. MiRNA expression was measured using quantitative real-time PCR. Colony formation and MTT assays were used to test cell proliferation. Luciferase assay, immunohistochemistry and Western blotting were employed to explore the molecular mechanism. RESULTS: MiR-142-3p level was found as the most significantly repressed miRNA in CRC patients. Overexpression of miR-142-3p dramatically repressed colony formation and cell proliferation of both HT29 and HCT116 cells while inhibition of miR-142-3p promoted those of the cells. Interestingly, overexpression of miR-142-3p reduced the level and nuclear accumulation of ß-catenin. We further observed that miR-142-3p remarkably inhibited the transcriptional activity of ß-catenin gene (CTNNB1). However, mutations in the predicted binding sites blocked this inhibition, suggesting that miR-142-3p may directly bind to the mRNA of ß-catenin. CONCLUSION: In conclusion, we identified miR-142-3p exerts its function as a tumor suppressor through blocking the activation of Wnt signaling by directly targeting to CTNNB1.

Vacuolar Membrane ATPase Activity 21 Predicts a Favorable Outcome and Acts as a Suppressor in Colorectal Cancer.

Extracellular and/or intracellular manipulation of pH in tumor may have noticeable potential in cancer treatment. Although the assembly factor genes of V0 domain of the V-ATPase complex are required for intracellular pH homeostasis, their significance in colorectal cancer (CRC) remains largely unknown. Here, we used bioinformatics to identify the candidates from known assembly factor genes of the V0 domain, which were further evaluated by immunohistochemistry (IHC) in CRC and adjacent normal specimens from 661 patients. Univariate and multivariate Cox analyses were used to evaluate factors contributing to prognosis. The effects of variations in the expression of VMA21 on tumor growth were assessed in vitro and in vivo. Of five known assembly factors, only VMA21 showed differential expression between CRC and adjacent normal tissues at both mRNA and protein levels. Patients with high VMA21 expression had higher differentiation grade and longer disease-specific survival (DSS) at stages I-III disease. High VMA21 expression in tumors was also an independent predictor of DSS (hazard ratio, 0.345; 95% confidence interval, 0.123-0.976), with covariates included TNM stage and differentiation grade. VMA21 overexpression decreased CRC growth, whereas VMA21 knockdown increased CRC growth in vitro and in vivo. VMA21 expression suppresses CRC growth and predicts a favorable DSS in patients with stage I-III disease.

Low tumour PPM1H indicates poor prognosis in colorectal cancer via activation of cancer-associated fibroblasts.

BACKGROUND: Vimentin (VIM) is considered a prognostic marker in colorectal cancer (CRC). Our aim is to identify genes that fulfil a "X-low implies VIM-high" Boolean relationship and to evaluate their prognostic value and potential mechanism. METHODS: Potential biomarkers related to VIM expression were searched using a bioinformatics approach across gene-expression arrays. Based on subgroup analysis of 2 CRC cohorts, the selected gene was tested for its association with patient's survival outcomes. The regulatory link between the selected gene and VIM was further examined with in vitro models. RESULTS: PPM1H was identified as the top candidate in our search. Patients with PPM1H-low tumours have a lower 5-year disease-free survival rate than patients with PPM1H-high tumours in 2 independent cohorts. In multivariate Cox analysis, patients with PPM1H-low tumours were independently associated with relapse in both the discovery cohort (hazard ratio [HR], 1.362; 95% confidence interval [CI], 1.015-1.826; P = 0.039) and the validation cohort (HR for DFS, 4.052; 95% CI, 2.634-6.234; P < 0.001). PPM1H knockdown in CRC cells and growth in the corresponding conditional medium increased VIM expression and colon fibroblast proliferation, indicating a transformation of cancer-association fibroblasts (CAFs). Conversely, educated CAFs also facilitated the growth of CRC cells with low PPM1H expression. CONCLUSIONS: Lack of tumour PPM1H expression identifies a patient subgroup with a high relapse risk, and CRC cells with low expression of PPM1H activate CAFs and inversely get promoted by CAFs.

Basic transcription factor 3 expression silencing attenuates colon cancer cell proliferation and migration in vitro.

Basic transcription factor 3 (BTF3) is an RNA polymerase II transcription factor that also regulates apoptosis. Numerous studies have identified that BTF3 is aberrantly expressed in several types of tumor. However, the function of BTF3 in colorectal cancer remains unknown. The aim of the present study was to assess the function of BTF3 during colon cancer tumorigenesis. Applying a lentivirus-transfected short hairpin RNA approach, expression of BTF3 was dysregulated in the colon cancer HCT116 and HT-29 cell lines; knockdown efficiency was verified using the quantitative polymerase chain reaction and western blotting. To determine the function of BTF3 in colon cancer, cell proliferation was assessed using an MTT assay, cell apoptosis and the cell cycle were assessed using flow cytometry, and cell migration was assessed using a Transwell assay. Knockdown of BTF3 inhibited cell proliferation, possibly because BTF3 knockdown induced cell early apoptosis and arrested cells in G0-G1 phase. BTF3 knockdown also inhibited cell migration. The results of the present study identified that BTF3 expression is associated with colon cancer progress, and BTF3 may therefore be a molecular marker for diagnosis and treatment outcomes of human colon cancer.

Embolization of blood-supply artery followed by surgery for treatment of mesorectal Castleman's disease: case report and literature review.

A 23-year-old male patient was diagnosed as having a hypervascular pelvic mass by ultrasonography and magnetic resonance examination. A pathology puncture showed vitreous vascular Castleman's disease. Because of concerns about tumor blood supply, embolization under digital subtraction angiography (DSA) was performed on the artery of the pelvic tumor before resection of the mass and surrounding rectum. Castleman's disease of pelvic lymph node (mixed type, mainly hyaline vascular type) was confirmed pathologically from postoperative biopsy. Embolization of the blood-supply artery of a hypervascular mass should be considered before surgery is performed.

Clinical significance and biological function of WD repeat domain 54 as an oncogene in colorectal cancer.

In recent years, protein-protein interactions have become an attractive candidate for identifying biomarkers and drug targets for various diseases. However, WD40 repeat (WDR) domain proteins, some of the most abundant mediators of protein interactions, are largely unexplored. In our study, 57 of 361 known WDR proteins were identified as hub nodes, and a hub (WDR54) with elevated mRNA in colorectal cancer (CRC) was selected for further study. Immunohistochemistry of specimens from 945 patients confirmed the elevated expression of WDR54 in CRC, and we found that patients with WDR54-high tumors typically had a shorter disease-specific survival (DSS) than those with WDR54-low tumors, especially for the subgroup without well-differentiated tumors. Multivariate analysis showed that WDR54-high tumors were an independent risk factor for DSS, with a hazard ratio of 2.981 (95% confidence interval, 1.425-6.234; p = 0.004). Knockdown of WDR54 significantly inhibited the growth and aggressiveness of CRC cells and reduced tumor growth in a xenograft model. Each WDR54 isoform (a, b, and c) was found to reverse the inhibitory effect of WDR54 knockdown; however, only isoform c, which exhibited the highest expression, was increased in CRC cells. Sensitization of WDR54 knockdown to an SHP2 inhibitor was consistently found in CRC cells, and the underlying mechanism involved their common function in regulating AKT and ERK signaling. In conclusion, the present study is the first to investigate the significance of WDR54 in cancer and to conclude that WDR54 serves as an oncogene in CRC and may be a potential prognostic marker and therapeutic target.

Eyes absent homologue 2 predicts a favorable prognosis in colorectal cancer.

PURPOSE: Eyes absent homologue 2 (EYA2), which functions as a transcription activator and phosphatase, plays an important role in several types of cancer. However, the impact of EYA2 in colorectal cancer (CRC) remains elusive. PATIENTS AND METHODS: We evaluated the significance of EYA2 expression in the development and progression of CRC in a large cohort, including 922 CRC cases. EYA2 protein expression was determined via immunohistochemistry in colorectal tissues. The correlation between EYA2 expression and CRC occurrence was investigated in tumor tissue and the adjacent normal tissues. Factors contributing to CRC prognosis were evaluated using Kaplan-Meier and Cox model analyses. RESULTS: EYA2 expression was progressively lower in the adjacent normal tissue, adenomas, primary tumor and the metastatic CRC (all P<0.05). Furthermore, EYA2 expression had significant associations with disease stage, differentiation grade, and number of resected lymph nodes (all P<0.001). Compared with patients with EYA2-high tumors, those with EYA2-low tumors had shorter disease-free survival (hazard ratio [HR], 2.347; 95% CI, 1.665-3.308) and disease-specific survival (HR, 3.560; 95% CI, 2.055-6.167) in multivariate Cox analysis, after adjusting confounding factors such as tumor-node-metastasis stage and grade. In particular, patients with stage II or III EYA2-low CRC might be harmed by postoperative chemotherapy. CONCLUSION: EYA2 expression was generally reduced in CRC. Higher EYA2 expression can predict a more favorable prognosis for CRC.

SHP2 associates with nuclear localization of STAT3: significance in progression and prognosis of colorectal cancer.

Tyrosine phosphatase SHP2, encoded by PTPN11, has been implicated in many physiologic and pathologic processes in neoplastic progression. However, controversies are emerging from many studies, indicating SHP2 has a dual role in different types of tumors. We aimed to explore the role of SHP2 in progression and prognosis of colorectal cancer (CRC). SHP2 inhibited CRC cell proliferation and migration, and the phosphorylation of STAT3 was negatively regulated by SHP2 in CRC. SHP2 and nuclear STAT3 were examined in 270 CRC tissues. SHP2 was significantly correlated with nuclear STAT3 (Spearman's rho = -0.408, P ≤ 0.001). Based on Cox regression analysis, patients with high levels of SHP2 and low levels of nuclear STAT3 had longer disease-specific survival (DSS) (HR, 0.362; 95% CI, 0.165-0.794) and disease-free survival (DFS) (HR, 0.447; 95% CI, 0.227-0.877). Further, low levels of SHP2 and high levels of nuclear STAT3 were independently associated with adverse outcomes in the whole cohort (DFS; HR, 2.353; 95% CI, 1.199-4.619). These results suggest that combination of SHP2 and nuclear STAT3 is a strong prognostic predictor in CRC.

Significance of the E3 ubiquitin protein UBR5 as an oncogene and a prognostic biomarker in colorectal cancer.

The E3 ubiquitin protein UBR5 has been implicated in the regulation of multiple biological functions and has recently emerged as a key regulator of the ubiquitin-proteasome system (UPS) in cancer. However, the clinical significance and biological function of UBR5 in colorectal cancer (CRC) are poorly understood. In this study, we compared the expression pattern of UBR5 between CRC and adjacent normal tissues and found that UBR5 expression was frequently elevated in CRC, possibly through chromosomal gains. Using three CRC patient cohorts, we found that patients with high UBR5 mRNA levels, UBR5 gene amplification, or high nuclear UBR5 protein levels had poor prognoses. Multivariate analysis showed that the alterations in UBR5 were independent predictors of CRC prognosis with the TNM stage as a confounding factor. Furthermore, knockdown of UBR5 prevented the proliferation, colony formation, migration, and invasion of CRC cells in cell culture models. An in vivo animal model further confirmed that UBR5 knockdown reduced the growth of CRC tumors. In conclusion, our study is the first to systematically investigate the clinical and biological significance of UBR5 and to conclude that an elevated UBR5 level plays an oncogenic role and may be a potential prognostic marker in CRC.

miR-320b suppresses cell proliferation by targeting c-Myc in human colorectal cancer cells.

BACKGROUND: MicroRNAs (miRNAs) are small noncoding RNAs that potentially play a critical role in tumorigenesis. Mounting evidence indicates that one specific miRNA: miR-320b is down regulated in numerous human cancers, including colorectal cancer (CRC); making the hypothesis that miR-320b may play a key role in tumorigenesis plausible. However, its role in carcinogenesis remains poorly defined. The goal of this study is to better clarify the role of miR-320b in tumor growth of CRC. METHODS: Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was conducted to detect the expression of miR-320b in CRC tissues and 5 CRC cell lines. The effect of miR-320b on cell proliferation was analyzed in vitro and in vivo. Furthermore, a luciferase reporter assay was performed to measure the target effects of miR-320b. Lastly, the messenger RNA (mRNA) and protein levels of the gene c-MYC were measured in CRC cell lines and tissues by qRT-PCR, and confirmed via Western blot and Immunohistochemical (IHC) staining. RESULTS: The results presented here showed that miR-320b expression was down regulated in both CRC tissues and cells. Overexpression of miR-320b in CRC cells was statistically correlated with a decrease of cell growth in vitro and in vivo, while c-MYC was identified as a target gene of miR-320b in CRC. Furthermore, it was found that up-regulation of c-Myc can attenuate the effects induced by miR-320b. CONCLUSIONS: Our identification of c-MYC as a target gene of miR-320b provides new insights into the pathophysiology of CRC proliferation, and identifies miR-320b as a novel therapeutic target for the treatment of CRC.

RPS24 knockdown inhibits colorectal cancer cell migration and proliferation in vitro.

Besides new proteins synthesis, ribosomal protein has a role in extra-ribosomal functions, which are related to many diseases, such as Diamond-Blackfan anemia, hypoplasia, and cell apoptosis. However, the importance of RPS24 in human colon cancer is largely unknown. In this study, RPS24 gene expression was significantly inhibited in human colon cancer HCT116 and HT-29 cells using a lentivirus shRNA approach. Knockdown of RPS24 expression significantly inhibited cell proliferation, colony formation, cell migration and arrested cell in S phase. The results demonstrated for the first time that RPS24 gene had a critical role in human colon cancer. Therefore, our findings indicated that RPS24 gene may be a promising biomarker for therapy in human colon cancer and may have a potential application in the diagnosis or treatment of human colon cancer.

Lentivirus-mediated silencing of USO1 inhibits cell proliferation and migration of human colon cancer cells.

Belonging to the tether factors family, USO1 (vesicle transport factor) plays a critical role in endoplasmic reticulum-Golgi trafficking and vesicular transport which is important to tumorigenesis. However, the mechanism of USO1 in colon cancer was still unknown. In our research, the expression of USO1 was knockdown in colon cancer cells (HCT116 and HT-29) by using a special lentivirus shRNA approach. A series of experiments were carried out to evaluate the effect of deregulation of USO1, including cell proliferation, apoptosis, cell migration and cell cycle. Knockdown of USO1 inhibits the ability of cell proliferation and migration. Furthermore, the deregulation of USO1 induces early apoptosis and decreased cells in G2-M phase. We demonstrate for the first time that USO1 gene has a critical role in human colon cancer. Our finding represents that USO1 gene may be a promising target for therapy and diagnosis in treatment of human colon cancer.