Early detection and prognosis prediction for colorectal cancer by circulating tumour DNA methylation haplotypes: A multicentre cohort study.

Background: Early detection and prognosis prediction of colorectal cancer (CRC) can significantly reduce CRC-related mortality. Recently, circulating tumour DNA (ctDNA) methylation has shown good application foreground in the early detection and prognosis prediction of multiple tumours. Methods: This multicentre cohort study evaluated ctDNA methylation haplotype patterns based on archived plasma samples (collected between 2010 and 2018) from 1138 individuals at two medical centres: Fudan University Shanghai Cancer Center (Shanghai, China) and Southern Medical University Nanfang Hospital (Guangzhou, Guangdong, China), including 366 healthy individuals, 182 patients with advanced adenoma (AA), and 590 patients with CRC. Samples were processed using the ColonES assay, a targeted bisulfite sequencing method that detects ctDNA methylation haplotype patterns in 191 genomic regions. Among these 1138 samples, 748 were used to develop a classification model, and 390 served as a blinded cohort for independent validation. The study is registered at https://register.clinicaltrials.gov with the unique identifier NCT03737591. Results: The model obtained from unblinded samples discriminated patients with CRC or AA from normal controls with high accuracy. In the blinded validation set, the ColonES assay achieved sensitivity values of 79.0% (95% confidence interval (CI), 66%-88%) in AA patients and 86.6% (95% CI, 81%-91%) in CRC patients with a specificity of 88.1% (95% CI, 81%-93%) in healthy individuals. The model area under the curve (AUC) for the blinded validation set was 0.903 for AA samples and 0.937 for CRC samples. Additionally, the prognosis of patients with high preoperative ctDNA methylation levels was worse than that of patients with low ctDNA methylation levels (p = 0.001 for relapse-free survival and p = 0.004 for overall survival). Interpretation: We successfully developed and validated an accurate, noninvasive detection method based on ctDNA methylation haplotype patterns that may enable early detection and prognosis prediction for CRC. Funding: The Grant of National Natural Science Foundation of China (No.81871958), National Natural Science Foundation of China (No. 82203215), Shanghai Science and Technology Committee (No. 19140902100), Scientific Research Fund of Fudan University (No.IDF159052), Shanghai Municipal Health Commission (SHWJRS 2021-99), and Shanghai Sailing Program (22YF1408800).

PTPRO represses colorectal cancer tumorigenesis and progression by reprogramming fatty acid metabolism.

BACKGROUND: Abnormal expression of protein tyrosine phosphatases (PTPs) has been reported to be a crucial cause of cancer. As a member of PTPs, protein tyrosine phosphatase receptor type O (PTPRO) has been revealed to play tumor suppressive roles in several cancers, while its roles in colorectal cancer (CRC) remains to be elucidated. Hence, we aimed to explore the roles and mechanisms of PTPRO in CRC initiation and progression. METHODS: The influences of PTPRO on the growth and liver metastasis of CRC cells and the expression patterns of different lipid metabolism enzymes were evaluated in vitro and in vivo. Molecular and biological experiments were conducted to uncover the underpinning mechanisms of dysregulated de novo lipogenesis and fatty acid ß-oxidation. RESULTS: PTPRO expression was notably downregulated in CRC liver metastasis compared to the primary cancer, and such a downregulation was associated with poor prognosis of patients with CRC. PTPRO silencing significantly promoted cell growth and liver metastasis. Compared with PTPRO wild-type mice, PTPRO-knockout mice developed more tumors and harbored larger tumor loads under treatment with azoxymethane and dextran sulfate sodium. Gene set enrichment analysis revealed that PTPRO downregulation was significantly associated with the fatty acid metabolism pathways. Blockage of fatty acid synthesis abrogated the effects of PTPRO silencing on cell growth and liver metastasis. Further experiments indicated that PTPRO silencing induced the activation of the AKT serine/threonine kinase (AKT)/mammalian target of rapamycin (mTOR) signaling axis, thus promoting de novo lipogenesis by enhancing the expression of sterol regulatory element-binding protein 1 (SREBP1) and its target lipogenic enzyme acetyl-CoA carboxylase alpha (ACC1) by activating the AKT/mTOR signaling pathway. Furthermore, PTPRO attenuation decreased the fatty acid oxidation rate by repressing the expression of peroxisome proliferator-activated receptor alpha (PPARα) and its downstream enzyme peroxisomal acyl-coenzyme A oxidase 1 (ACOX1) via activating the p38/extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) signaling pathway. CONCLUSIONS: PTPRO could suppress CRC development and metastasis via modulating the AKT/mTOR/SREBP1/ACC1 and MAPK/PPARα/ACOX1 pathways and reprogramming lipid metabolism.

Bulk and single-cell transcriptome profiling reveal necroptosis-based molecular classification, tumor microenvironment infiltration characterization, and prognosis prediction in colorectal cancer.

BACKGROUND: Necroptosis is a new form of programmed cell death that is associated with cancer initiation, progression, immunity, and chemoresistance. However, the roles of necroptosis-related genes (NRGs) in colorectal cancer (CRC) have not been explored comprehensively. METHODS: In this study, we obtained NRGs and performed consensus molecular subtyping by "ConsensusClusterPlus" to determine necroptosis-related subtypes in CRC bulk transcriptomic data. The ssGSEA and CIBERSORT algorithms were used to evaluate the relative infiltration levels of different cell types in the tumor microenvironment (TME). Single-cell transcriptomic analysis was performed to confirm classification related to NRGs. NRG_score was developed to predict patients' survival outcomes with low-throughput validation in a patients' cohort from Fudan University Shanghai Cancer Center. RESULTS: We identified three distinct necroptosis-related classifications (NRCs) with discrepant clinical outcomes and biological functions. Characterization of TME revealed that there were two stable necroptosis-related phenotypes in CRC: a phenotype characterized by few TME cells infiltration but with EMT/TGF-pathways activation, and another phenotype recognized as immune-excluded. NRG_score for predicting survival outcomes was established and its predictive capability was verified. In addition, we found NRCs and NRG_score could be used for patient or drug selection when considering immunotherapy and chemotherapy. CONCLUSIONS: Based on comprehensive analysis, we revealed the potential roles of NRGs in the TME, and their correlations with clinicopathological parameters and patients' prognosis in CRC. These findings could enhance our understanding of the biological functions of necroptosis, which thus may aid in prognosis prediction, drug selection, and therapeutics development.

Ferroptosis-associated molecular classification characterized by distinct tumor microenvironment profiles in colorectal cancer.

Ferroptosis is a non-apoptotic form of cell death recognized in recent years. Nonetheless, the potential role of ferroptosis-associated genes in immune regulation and tumor microenvironment formation remains unknown. In this study, we characterized the ferroptosis-associated patterns of colorectal cancer through integrative analyses of multiple datasets with transcriptomics, genomics, and single-cell transcriptome profiling. Three distinct ferroptosis-associated clusters (FAC1, FAC2 and FAC3) were identified from 1251 CRC bulk samples, which were associated with different clinical outcomes and biological pathways. The TME characterization revealed that the three patterns were highly consistent with known immune profiles: immune-desert (FAC1), immune-inflamed (FAC2) and immune-excluded (FAC3), respectively. Ferroptosis-associated immune and stromal-activated genes were obtained and characterized by corresponding function in CRC tumorigenesis. Further single-cell analyses identified the ferroptosis-associated immune responding tumor cells and ferroptosis-associated stromal cells infiltration pattern. Based on the Fersig score, which was extracted from the ferroptosis phenotype-related signature, patients with lower Fersig score were characterized by prolonged survival time and effective immune responses. Collectively, we uncovered the ferroptosis-associated patterns associated with TME diversity and immune response phenotype. The Fersig we constructed could be the potential therapeutic target genes to improve the efficacy of patients' immunotherapy. The Fersig scoring scheme could enhance the understanding of TME infiltration associated with ferroptosis and prediction of immunotherapy efficacy.

Comprehensive Transcriptomic Analysis Reveals Prognostic Value of an EMT-Related Gene Signature in Colorectal Cancer.

Lymph node metastasis (LNM) is closely related to the postoperative recurrence of colorectal cancer (CRC), and greatly affects patient survival. Conducting Gene set variation analysis (GSVA) and gene set enrichment analysis (GSEA), we found that the epithelial-mesenchymal transition (EMT) signaling pathway is the signaling pathway most relevant to the process of LNM. An EMT-related gene signature was identified from a discovery dataset obtained 489 patients using LIMMA and LASSO Cox methods. Six external independent dataset analyses including a total of 1,045 CRC patients and stratification analysis showed that EMT-related gene signature could sort out those high- and low-risk CRC patients accurately. Functional analysis and loss-of-function exploration in vitro and in vivo indicated that the EMT-related-signature-associated coding genes might play functional roles in the sophisticated regulation of CRC proliferation and metastasis. Prognostic nomograms integrating the EMT-related gene signature and clinicopathological risk factors were constructed for use as numerical prediction tools to assess clinical prognosis and clinical decision-makings. The comprehensive transcriptomic analysis in this article highlights the prognostic value of an EMT-related gene signature for postoperative disease recurrence in CRC patients and reveals a potential prognostic and therapeutic biomarker for CRC.

Nomogram of conditional survival probability of long-term Survival for Metastatic Colorectal Cancer: A Real-World Data Retrospective Cohort Study from SEER database.

BACKGROUND: Many patients with metastatic colorectal cancer (mCRC) have better prognosis than the prediction at diagnosis. Compared with invariable traditional Kaplan Meier assessment, conditional survival (CS) assessment has become a more accurate and informative assessment method to predict survival time. MATERIALS AND METHODS: Patients with mCRC between 2010 and 2015 were extracted from Surveillance, Epidemiology and End Results linked database. CS analysis was applied to depict exact survival for patients who have survived for specific year and standardized difference (d) was used to evaluate the differences between subgroups in CS analysis. Based on variables selected by Lasso analysis, nomograms for each year after diagnosis were fitted to estimate 3-year survival of stage IV CRC, respectively. RESULTS: Of 9732 patients, overall actuarial survival (OS) decreased from 24% at 4-year to 16% at 6-year, while corresponding 3-year CS (CS3) increased from 33% at 1-year to 48% at 3-year. Overall, CS3 was higher than corresponding actuarial survival. All clinicopathological characteristics were associated with actuarial survival (p < 0.05). However, in CS3 analysis, survival difference caused by gender, race and tumor size gradually disappeared over time (|d|>0.1→ |d|<0.1). Furthermore, survival difference caused by histological type, brain metastasis and chemotherapy reversed over time (d > 0→d<0 or d<0→d>0). Based on lasso analysis, nomograms for 1st, 2nd and 3rd year after diagnosis were conducted respectively. The AUC of nomogram for 1st year was 0.705, for 2nd year was 0.675, and for 3rd year was 0.648. CONCLUSION: Patients with mCRC demonstrated a substantial increase in CS over time. Risk factors collected at diagnosis may change gradually. Nomograms constructed by survival time can predict more accurate survival for patients with mCRC. Conditional survival assessments provide important quantitative information about the probability of survival and are therefore of great value to patients and health care professionals.

Fecal Multidimensional Assay for Non-Invasive Detection of Colorectal Cancer: Fecal Immunochemical Test, Stool DNA Mutation, Methylation, and Intestinal Bacteria Analysis.

BACKGROUND: Fecal immunochemical test (FIT), DNA mutation, DNA methylation, and microbial dysbiosis all showed promising in colorectal cancer (CRC) non-invasive detection. We assessed CRC detection with an assay combining all these strategies and investigated the effect of clinical features on the performance of this comprehensive test. METHODS: We performed a multidimensional analysis study using stool samples collected from 108 patients with CRC, 18 patients with colorectal adenoma, and 36 individuals with no evidence of colorectal disease. The multidimensional analysis of stool samples including FIT, stool DNA (sDNA) tests for three methylated genes (Septin9, NDRG4, BMP3) and three mutated genes (KRAS, BRAF, PI3KCA) using next generation sequencing as well as detection of stool bacteria level of Fusobacterium nucleatum and Parvimonas micra using qPCR method. We used a linear support vector classification model to analyze the data. RESULTS: The sensitivity of FIT alone was 69.4% for CRC and 11.1% for adenoma. Separately, the sensitivity of the detection of intestinal bacteria, DNA mutation, and DNA methylation for CRC was 58.3, 50.0, and 51.9%, respectively. The combination of FIT and sDNA tests had a sensitivity of 81.5% for CRC (AUC: 0.93, better than FIT alone, P = 0.017) and 27.8% for adenoma with 94.4% specificity. Sensitivity of the multidimensional test to detect CRC with stage II (84.6%) and III (91.9%) CRC was relatively higher (88.2%) than that of patients with stage I (60.0%) and stage IV (75.0%) (P = 0.024). The rate of CRC detection increased with tumor size (P = 0.008) and age (P = 0.04). Interestingly, the rate of CRC detection was higher in smoking persons than non-smokers with marginal significance (P = 0.08). CONCLUSIONS: The multidimensional assay of stool samples combining FIT and stool DNA tests further improved the diagnostic sensitivity for CRC. This could provide new approach for improvement of CRC screening and further demonstrations are warranted.

Preoperative prediction of peritoneal metastasis in colorectal cancer using a clinical-radiomics model.

PURPOSE: To establish and validate a combined clinical-radiomics model for preoperative prediction of synchronous peritoneal metastasis (PM) in patients with colorectal cancer (CRC). METHOD: We enrolled 779 patients (585 in the training set: 553 with nonmetastasis (NM) and 32 with PM; 194 in the validation set: 184 with NM and 10 with PM) with clinicopathologically confirmed CRC. The significant clinical risk factors were used to build the clinical model; the least absolute shrinkage and selection operator (LASSO) algorithm was adopted to construct a radiomics signature, which included imaging features of the primary lesion and the largest peripheral lymph node, and stepwise logistic regression was applied to select the significant variables to develop the clinical-radiomics model. We used the Akaike information criterion (AIC) and receiver operating characteristic analysis to compare the goodness of fit and the prediction performance of the three models respectively. An independent validation cohort, containing 139 consecutive patients from February to September 2018, was used to evaluate the performance of the optimal model. RESULTS: Among the three models, the clinical-radiomics model (AUC = 0.855; AIC = 1043.2) was identified as the optimal model, with the maximum AUC value and the minimum AIC value (the clinical-only model: AUC = 0.771, AIC = 1277.7; the radiomics-only model: AUC = 0.764, AIC = 1280.5). The clinical-radiomics model also showed good discrimination in both the validation cohort (AUC = 0.793) and the independent validation cohort (AUC = 0.781). CONCLUSIONS: The present study proposes a clinical-radiomics model created with the CT-based radiomics signature and key clinical features that can potentially be applied in the individual preoperative prediction of synchronous PM for CRC patients.

GLUT3 induced by AMPK/CREB1 axis is key for withstanding energy stress and augments the efficacy of current colorectal cancer therapies.

Cancer cells are usually characterized by hyperactive glucose metabolism, which can often lead to glucose scarcity; thus, alternative pathways to rewire cancer metabolism are required. Here, we demonstrated that GLUT3 was highly expressed in colorectal cancer (CRC) and negatively linked to CRC patient outcomes, whereas GLUT1 was not associated with CRC prognosis. Under glucose-limiting conditions, GLUT3 expedited CRC cell growth by accelerating glucose input and fuelling nucleotide synthesis. Notably, GLUT3 had a greater impact on cell growth than GLUT1 under glucose-limiting stress. Mechanistically, low-glucose stress dramatically upregulated GLUT3 via the AMPK/CREB1 pathway. Furthermore, high GLUT3 expression remarkably increased the sensitivity of CRC cells to treatment with vitamin C and vitamin C-containing regimens. Together, the results of this study highlight the importance of the AMPK/CREB1/GLUT3 pathway for CRC cells to withstand glucose-limiting stress and underscore the therapeutic potential of vitamin C in CRC with high GLUT3 expression.

Modeling tumor development and metastasis using paired organoids derived from patients with colorectal cancer liver metastases.

Tumor metastasis accounts for the majority of cancer-related deaths; it is therefore important to develop preclinical models that faithfully recapitulate disease progression. Here, we generated paired organoids derived from primary tumors and matched liver metastases in the same colorectal cancer (CRC) patients. Despite the fact that paired organoids exhibit comparable gene expression and cell morphology, organoids from metastatic lesions demonstrate more aggressive phenotypes, tumorigenesis, and metastatic capacity than those from primary lesions. Transcriptional analyses of the paired organoids reveal signature genes and pathways altered during the progression of CRC, including SOX2. Further study shows that inducible knockdown of SOX2 attenuated invasion, proliferation, and liver metastasis outgrowth. Taken together, we use patient-derived paired primary and metastatic cancer organoids to model CRC metastasis and illustrate that SOX2 is associated with CRC progression and may serve as a potential prognostic biomarker and therapeutic target of CRC.

Prognostic and predictive value of radiomics signatures in stage I-III colon cancer.

Accurate identification of patients with poor prognosis after radical surgery is essential for clinical management of colon cancer. Thus, we aimed to develop death and relapse specific radiomics signatures to individually estimate overall survival (OS) and relapse free survival (RFS) of colon cancer patients. In this study, 701 stage I-III colon cancer patients were identified from Fudan University Shanghai Cancer Center. A total of 647 three-dimensional features were extracted from computed tomography images. LASSO Cox was used to identify the significantly death- and relapse-associated features and to build death and relapse specific radiomics signatures, respectively. A total of 13 death-specific and 26 relapse-specific features were identified from 647 screened radiomics features. The developed signatures can divide patients into two groups with significantly different death (Hazard Ratio (HR): 3.053; 95% CI, 1.78-5.23; P < .001) or relapse risk (HR: 2.794; 95% CI, 1.87-4.16; P < .001). Time-dependent Relative operating characteristic curve showed that the signatures performed better than any other clinicopathological factors in predicting OS (AUC: 0.768; 95% CI, 0.745-0.791) and RFS (AUC: 0.744; 95% CI, 0.687-0.801). Further, survival decision curve analyses confirmed the good clinical utility of the two radiomics signatures. In conclusion, we successfully developed death- and relapse-specific radiomics signatures that can accurately predict OS and RFS, which may facilitate personalized treatment.

Development and external validation of a predictive scoring system associated with metastasis of T1-2 colorectal tumors to lymph nodes.

BACKGROUND: It is critical for determining the optimum therapeutic solutions for T1-2 colorectal cancer (CRC) to accurately predict lymph node metastasis (LNM) status. The purpose of the present study is to establish and verify a nomogram to predict LNM status in T1-2 CRCs. METHODS: A total of 16 600 T1-2 CRC patients were enrolled and classified into the training, internal validation, and external validation cohorts. The independent predictive parameters were determined by univariate and multivariate analyses to develop a nomogram to predict the probability of LNM status. The calibration curve, the area under the receiver operating characteristic curve (AUROC), and decision curve analysis (DCA) were used to evaluate the performance of the nomogram, and an external verification cohort was to verify the applicability of the nomogram. RESULTS: Seven independent predictors of LNM in T1-2 CRC were identified in the multivariable analysis, including age, tumor site, tumor grade, perineural invasion, preoperative carcinoembryonic antigen, clinical assessment of LNM, and T stage. A nomogram incorporating the seven predictors was constructed. The nomogram yielded good discrimination and calibration, with AUROCs of 0.72 (95% confidence interval [CI]: 0.70-0.75), 0.70 (95% CI: 0.67-0.74), and 0.74 (95% CI: 0.71-0.79) in the training, internal validation, and external validation cohorts, respectively. DCA showed that the predictive scoring system had high clinical application value. CONCLUSIONS: We proposed a novel predictive model for LNM in T1-2 CRC patients to assist physicians in making treatment decisions. The nomogram is advantageous for tailoring therapy in T1-2 CRC patients.

Enhanced glutamine utilization mediated by SLC1A5 and GPT2 is an essential metabolic feature of colorectal signet ring cell carcinoma with therapeutic potential.

BACKGROUND: Colorectal signet-ring cell carcinoma (SRCC) is characterized as a rare subset of colorectal cancer with extremely poor prognosis and it is known to have low or negative 18F fluorodeoxyglucose (18F-FDG) uptake. To date, no in-depth study revealing the metabolic features of colorectal SRCC has been conducted for the lack of reliable study model. The aim of this study was to explore the distinct characteristics of energy utilization for colorectal SRCC based on organoid model. METHODS: Three organoids were derived from colorectal SRCC patients with low or negative FDG uptake and three organoids were derived from colorectal adenocarcinoma (AC) patients. Glucose, fatty acid and glutamine uptake assays were performed to reveal the different metabolic features of SRCC organoids. Immunohistochemistry (IHC), western blotting and real-time PCR were used to test the expression of critical transporters and enzymes of energy metabolism. Glutamine deprivation analyses were used to confirm the dependence of colorectal SRCC on glutamine. RESULTS: Glucose, fatty acid and glutamine uptake assays showed that only glutamine uptake was significantly increased in colorectal SRCC organoids compared with paired normal organoids. Comparing SRCC organoids with AC organoids indicated that glucose and fatty acid uptake were strikingly higher in AC organoids while glutamine uptake was notably lower. Gene expression analyses confirmed that the glutamine transporter SLC1A5 and glutaminolysis enzyme GPT2 were significantly unregulated in colorectal SRCC. Silencing of SLC1A5 or GPT2 could suppress the proliferation of SRCC organoids but attenuating the sensitivity of SRCC to glutamine deprivation. Administration of SLC1A5 or GPT2 inhibitor could prohibit SRCC growth and significantly enhance the sensitivity of SRCC to the treatment of 5-fu and L-OHP. CONCLUSIONS: This study highlights enhanced glutamine uptake and glutaminolysis as a metabolic feature of colorectal SRCC and a potential therapeutic target.

Cause of death for elders with colorectal cancer: a real-world data analysis.

BACKGROUND: Many patients surviving from colorectal cancer die of causes irrelevant to cancer. This study was designed to describe the leading causes of death among older patients diagnosed with colorectal cancer and assess factors that are related to colorectal cancer mortality versus mortality from other causes. METHODS: Patients over 65-year-old diagnosed with colorectal cancer between 2000 and 2014 were extracted from Surveillance, Epidemiology, and End Results (SEER) linked database. RESULTS: A total of 136,872 patients with colorectal cancer met the inclusion criteria. The median follow-up time was approximately 3 years. Forty-five point seven percent of them were alive at the end of follow-up, and colorectal cancer still accounted for the most cases of deaths. However, patients with tumor of Grade I or TNM stage I-II were more likely to die from other causes. The fully-adjusted relative hazards ratio (HR) shows age, gender, tumor site, chemotherapy, tumor characteristics of grade and TNM stage affected both types of mortality. Race only affected mortality of other causes. Cardiovascular disease (CVD) was a noticeable cause of death among patients with stage I colorectal cancer. With longer follow-up, deaths due to colorectal cancer decreased while deaths of CVD, pulmonary diseases and other cause of death increased. CONCLUSIONS: Colorectal cancer still accounts for most deaths in elderly patients. However, comorbidities including CVD/COPD were associated with the deaths of colorectal cancer patients over 65. As survival time increases, comorbidities should be considered for cancer treatment. Management of CVD/COPD among elderly patients can help improve overall survival (OS) in colorectal cancer.

Nomogram to predict the risk and survival of synchronous bone metastasis in colorectal cancer: a population-based real-world analysis.

PURPOSE: Bone metastasis (BM) can obviously affect the quality of life of patients in colorectal cancer (CRC), and the whole management of patients with BM would be attractive in current clinical practice. METHODS: A total of 52,859 patients during 2010-2015 were collected from Surveillance, Epidemiology, and End Results (SEER) database. After propensity score matching (PSM), cancer-specific survival (CCS) and overall survival (OS) with BM were adopted to assess survival probability difference. Logistic regression was used to identify risk factors for BM; COX proportion hazard regression was applied to explore prognosticators for OS in patients with BM. Subsequently, nomograms were constructed and receiver operating curves (ROCs) were used to confirm the validation of nomogram. RESULTS: Three hundred and forty-two (0.65%) patients were diagnosed with synchronous BM. After PSM, 16 variables were balanced. Tumor site, histology, grade, T stage, N stage, CEA, radiochemotherapy, surgery, and liver/lung/brain metastases were associated with BM, and histology, grade, T stage, N stage, CEA, chemotherapy, surgery, and liver/lung metastases were prognosticators for BM survival. Nomograms were applied and the ROC curve proved the predictive effects. CONCLUSION: CRC patients with BM have worse real-world survival. Nomogram can predict incidence of BM in CRC patients and survival among patients with BM.

Antisense lncRNA LDLRAD4-AS1 promotes metastasis by decreasing the expression of LDLRAD4 and predicts a poor prognosis in colorectal cancer.

Long noncoding RNAs (lncRNAs) have been revealed to play critical roles in tumor initiation and progression. The antisense lncRNA LDLRAD4-AS1 is the longest lncRNA of LDLRAD4, and its expression levels, cellular localization, precise function, and mechanism in colorectal cancer (CRC) remain unknown. In this study, we observed that lncRNA LDLRAD4-AS1 was located in the nucleus of CRC cells and that lncRNA LDLRAD4-AS1 was upregulated in most CRC specimens and cell lines. Overexpression of lncRNA LDLRAD4-AS1 was correlated with poor prognosis in CRC patients. LncRNA LDLRAD4-AS1 upregulation enhanced the migration and invasion of CRC cells in vitro and facilitated CRC metastasis in vivo. Mechanistic investigations suggested that lncRNA LDLRAD4-AS1 could decrease the expression of LDLRAD4 by disrupting the stability of LDLRAD4 mRNA, resulting in epithelial-to-mesenchymal transition (EMT) through upregulating Snail, thereby promoting metastasis in CRC. Our results demonstrated a previously unrecognized LDLRAD4-AS1-LDLRAD4-Snail regulatory axis involved in epigenetic and posttranscriptional regulation that contributes to CRC progression and metastasis.

The Critical Role of Tumor Size in Predicting Prognosis for T1 Colon Cancer.

BACKGROUND: The role of horizontal growth index of tumor size in survival prediction is still underappreciated in colon cancer because of the identification of vertical infiltration index reflected by T stage. We sought to reveal the impact of T stage on the prognostic and predictive value of tumor size in colon cancer. MATERIALS AND METHODS: Data of patients with stage I-III colon cancer were extracted from Surveillance, Epidemiology, and End Results Program (SEER) and Fudan University Shanghai Cancer Center (FUSCC) databases. Harrell's concordance index (c-index) and time-dependent receiver operating characteristic curve (ROC) were used to analyze the discriminative ability of prognostic factors. RESULTS: Stratified analyses based on T stage found that the increase of T stage significantly and negatively repressed the effect of tumor size on death and recurrence risk. In addition, tumor size showed the greatest hazard ratio of cancer-specific death and relapse in T1 colon cancer. Even more importantly, the discriminatory ability of tumor size outperformed any other widely accepted prognostic clinical features in predicting cancer-specific survival (SEER: c-index 0.637, area under the ROC [AUC] 0.649; FUSCC: c-index 0.673, AUC 0.686) and disease-free survival (FUSCC: c-index 0.645, AUC 0.656) in T1 stage colon cancer. CONCLUSION: Tumor size is a critical clinical factor with considerable prognostic and predictive value for T1 colon cancer, and it should be selectively incorporated into the current staging system to facilitate prediction of death and recurrence risk. IMPLICATIONS FOR PRACTICE: To date, no consensus has been reached about the prognostic and predictive value of tumor size in colon cancer. Although tumor size is an independent prognostic factor for patients with colon cancer, the impact of tumor size on death or recurrence risk decreased notably with the increase of T stage. More importantly, the discriminative ability of tumor size outperformed any other clinical factors including N stage in patients with T1 colon cancer. Therefore, tumor size should be recommended to be incorporated into current staging systems to facilitate prognosis prediction for patients with T1 colon cancer.

Comparison of four lymph node staging systems for predicting prognosis for stage IV rectum cancer.

BACKGROUND: With recommendation of surgical management in primary site, both the positive and negative lymph nodes (LNs) retrieved have been emphasized to predict prognosis in stage IV rectum cancer. Therefore, we attempt to compare the prognostic performance of American Joint Committee on Cancer (AJCC) N-stage relative to lymph node ratio (LNR), log odds of metastatic lymph nodes (LODDS), and N-score in stage IV rectal cancer. METHODS: Total 5,090 patients taken surgical resection of primary site in rectum cancer with distant metastasis were extracted from Surveillance, Epidemiology, and End Results Program (SEER) database. Harrell's C statistic (C-index) and Akaike's Information Criterion (AIC) were used to evaluate the discriminative ability of the different LN staging systems. RESULTS: Of the 3,243 patients without radiotherapy, 82.46% (n=2,675) had been found with lymph nodes metastasis with median number of 16 lymph nodes collected (IQR: 11-22). Modeled as categorical cutoff variables for further clinical usage, when number of LNs was between 12 and 25 (C-index: 0.5997, AIC: 1,698.015), 8th AJCC N-stage outperformed other three schemas with increasing C-index and less AIC value. Assessed as continuous values, the LODDS shown as the best schemas with greatest discriminatory power (C-index: 0.5971, AIC: 3,680.017), generally. On the other hand, in the cohorts of other 1274 patients taken radiation, the median number of lymph nodes retrieved was 13 (IQR: 9-18). LODDS still remained remarkable performance as continuous (C-index: 0.5912; AIC: 1,058.765) and categorical variables (C-index: 0.5700; AIC: 1,061.703), while N-staging outperformed with less than 25 lymph nodes retrieved (LNs <12 C-index: 0.5678, AIC: 481.94; 12< LNs <25 C-index: 0.5933, AIC: 390.395). CONCLUSIONS: When assessed as categorical variables, N-stage performed superiorly with adequate lymph nodes examined, whether the patients have got radiotherapy prior to surgery or not. LODDS showed, when assessed as a continuous variable, good discriminative ability and goodness of fit in predicting survival for stage IV rectum cancer patients regardless of radiation therapy status.

FOXE1 represses cell proliferation and Warburg effect by inhibiting HK2 in colorectal cancer.

BACKGROUND: Low expression of FOXE1, a member of Forkhead box (FOX) transcription factor family that plays vital roles in cancers, contributes to poor prognosis of colorectal cancer (CRC) patients. However, the underlying mechanism remains unclear. MATERIALS AND METHODS: The effects of FOXE1 on the growth of colon cancer cells and the expression of glycolytic enzymes were investigated in vitro and in vivo. Molecular biological experiments were used to reveal the underlying mechanisms of altered aerobic glycolysis. CRC tissue specimens were used to determine the clinical association of ectopic metabolism caused by dysregulated FOXE1. RESULTS: FOXE1 is highly expressed in normal colon tissues compared with cancer tissues and low expression of FOXE1 is significantly associated with poor prognosis of CRC patients. Silencing FOXE1 in CRC cell lines dramatically enhanced cell proliferation and colony formation and promoted glucose consumption and lactate production, while enforced expression of FOXE1 manifested the opposite effects. Mechanistically, FOXE1 bound directly to the promoter region of HK2 and negatively regulated its transcription. Furthermore, the expression of FOXE1 in CRC tissues was negatively correlated with that of HK2. CONCLUSION: FOXE1 functions as a critical tumor suppressor in regulating tumor growth and glycolysis via suppressing HK2 in CRC.