UVRAG Promotes Tumor Progression through Regulating SP1 in Colorectal Cancer.

Colorectal cancer (CRC) is the third most common type of cancer. The ultraviolet radiation resistance-associated gene (UVRAG) plays a role in autophagy and has been implicated in tumor progression and prognosis. However, the role of UVRAG expression in CRC has remained elusive. In this study, the prognosis was analyzed via immunohistochemistry, and the genetic changes were compared between the high UVRAG expression group and the low UVRAG expression group using RNA sequencing (RNA-seq) and single-cell RNA-seq (scRNA-seq) data, and genetic changes were then identified by in vitro experiments. It was found that UVRAG could enhance tumor migration, drug resistance, and CC motif chemokine ligand 2 (CCL2) expression to recruit macrophages by upregulating SP1 expression, resulting in poor prognosis of CRC patients. In addition, UVRAG could upregulate the expression of programmed death-ligand 1 (PD-L1). In summary, the relationship between UVRAG expression and the prognosis of CRC patients as well as the potential mechanisms in CRC were explored, providing evidence for the treatment of CRC.

FAP promotes metastasis and chemoresistance via regulating YAP1 and macrophages in mucinous colorectal adenocarcinoma.

Mucinous colorectal adenocarcinoma (MC) is less likely to respond to chemotherapy and is associated with poorer prognosis compared with non-MC (NMC). Fibroblast activation protein (FAP) was found and validated to be upregulated in MC patients and was negatively correlated with prognosis and therapeutic outcomes in colorectal cancer (CRC) patients who were treated with adjuvant chemotherapy. Overexpression of FAP promoted CRC cell growth, invasion and metastasis, and enhanced chemoresistance. Myosin phosphatase Rho-interacting protein (MPRIP) was identified as a direct interacting protein of FAP. FAP may influence the efficiency of chemotherapy and prognosis by promoting the crucial functions of CRC and inducing tumor-associated macrophages (TAMs) recruitment and M2 polarization through regulating theRas Homolog Family Member/Hippo/Yes-associated protein (Rho/Hippo/YAP) signaling pathway. Knockdown of FAP could reverse tumorigenicity and chemoresistance in CRC cells. Thus, FAP may serve as a marker for prognosis and therapeutic outcome, as well as a potential therapeutic target to overcome chemoresistance in MC patients.

Predictive value of proteomic markers for advanced rectal cancer with neoadjuvant chemoradiotherapy.

BACKGROUND: Preoperative neoadjuvant chemoradiation (nCRT) has been the standard treatment for locally advanced rectal cancer. Serum biomarkers to stratify patients with respect to prognosis and response to nCRT are needed due to the diverse response to the therapy. METHODS: Thirteen paired pre- and post-nCRT sera from rectal cancer patients were analyzed by isobaric tags for relative and absolute quantitation (iTRAQ) method. Twenty-five proteins were selected for validation by parallel reaction monitoring (PRM) in ninety-one patients. RESULTS: Totally, 310 proteins were identified and quantified in sera samples. Reactome pathway analysis showed that the immune activation-related pathways were enriched in response to nCRT. Twenty-five proteins were selected for further validation. PRM result showed that the level of PZP was higher in pathological complete response (pCR) patients than non-pCR patients. The Random Forest algorithm identified a prediction model composed of 10 protein markers, which allowed discrimination between pCR patients and non-pCR patients (area under the curve (AUC) = 0.886 on testing set). Higher HEP2 and GELS or lower S10A8 in baseline sera were associated with better prognosis. Higher APOA1 in post nCRT sera was associated with better disease-free survival (DFS). CONCLUSIONS: We identified and confirmed a 10-protein panel for nCRT response prediction and four potential biomarkers HEP2, GELS, S10A8 and APOA1 for prognosis of rectal cancer based on iTRAQ-based comparative proteomics screening and PRM-based targeted proteomic validation.

Tumor mutation burden in blood predicts benefit from neoadjuvant chemo/radiotherapy in locally advanced rectal cancer.

Distant metastasis has been the major concern of prognosis in patients with locally advanced rectal cancer (LARC). The purpose of this study was to investigate the prognostic value of TMB in blood (bTMB) in LARC patients after receiving neoadjuvant chemoradiotherapy (nCRT) and surgery. Using targeted ctDNA sequencing, we revealed that bTMB level at baseline was positively correlated with recurrence-free survival (RFS). Following nCRT, the patients with decreasing TMB tends to have a longer median RFS. bTMB level after surgery was negatively correlated with RFS. The serum cytokines including IFNγ, IFNα2, IL-1ß, IL-2 and MIP-1ß were significantly higher in pre-nCRT serum with higher bTMB group than that of lower bTMB group. Clonal evolution analysis showed that the pre- and post-nCRT ctDNAs of most cases had shared mutations. In conclusion, we presume that bTMB could potentially improve pre- and post-treatment risk assessment and facilitate individualized therapy for patients with LARC.

Combination of radiotherapy and suppression of Tregs enhances abscopal antitumor effect and inhibits metastasis in rectal cancer.

BACKGROUND: Distant metastasis is the major cause of mortality in patients with locally advanced rectal cancer (LARC) following neoadjuvant chemoradiotherapy. Local radiotherapy can trigger an abscopal response to metastatic tumor cells. However, the abscopal effect is a rare event. CD4+ regulatory T (Treg) cell is a highly immune-suppressive subset which impedes immune surveillance against cancer, prevents the development of effective antitumor immunity and promotes tumor progression. We assume that the exploitation of the proimmunogenic effects of radiotherapy with anti-CD25 or anti-Cytotoxic T-Lymphocyte Associated Protein 4 (anti-CTLA4) monoclonal antibodies (mAbs) may enhance the local and abscopal effects in rectal cancer and improve the therapeutic outcome. METHODS: mRNA expression profiling of 81 pretreatment biopsy samples from LARC patients who received neoadjuvant radiotherapy (nRT) was performed to analyze the correlation between gene expression and prognosis. A retrospective analysis of patients with rectal cancer with distant metastasis or synchronous extracolonic cancers was performed to evaluate the abscopal effect of radiotherapy on rectal cancer. Two different dual-tumor mouse models were established to investigate the efficacy of single dose and dose-fractionated radiotherapy combined with anti-CD25 or anti-CTLA4 and anti-Programmed cell death 1 ligand 1 (anti-PD1) mAbs on the local tumor growth and liver metastasis. The univariate Cox regression analysis, one-way analysis of variance, Dunnett's test, a mixed-effect linear model and Kaplan-Meier survival analysis were used to calculate p values. RESULTS: The proportion of Tregs in pre-nRT biopsies was negatively correlated with prognosis (p=0.007). The retrospective analysis showed that regressing liver metastases were infiltrated by CD8+ T cells. In contrast, stable/progressing metastases and synchronous extracolonic cancers were characterized by PD1+ T cells and Tregs infiltration. Animal experiment results demonstrated that the combination of radiotherapy and anti-CD25/CTLA4 mAb resulted in a significant increase in CD8+ T cells and CD8+/CD4+ ratio in primary and secondary tumors compared with the irradiation alone group (all p<0.05 or p<0.01). The combined treatment was able to decrease Tregs, PD1+CD8+ and PD1+CD4+ T cells (p<0.05), suppress locally irradiated and distal unirradiated tumor growth, and improve overall survival rate. Radiotherapy in conjunction with anti-CTLA4 reduced liver metastasis (p<0.05). CONCLUSIONS: These data indicated that radiotherapy plus depletion of Tregs was able to improve the antitumor response and generate an abscopal effect.

Enhancement of Sensitivity to Chemo/Radiation Therapy by Using miR-15b against DCLK1 in Colorectal Cancer.

Chemo-/radiotherapy resistance is the main cause accounting for most treatment failure in colorectal cancer (CRC). Tumor-initiating cells (TICs) are the culprit leading to CRC chemo-/radiotherapy resistance. The underlying regulation mechanism of TICs in CRC remains unclear. Here we discovered that miR-15b expression positively correlated with therapeutic outcome in CRC. Expression of miR-15b in pretreatment biopsy tissue samples predicted tumor regression grade (TRG) in rectal cancer patients after receiving neoadjuvant radiotherapy (nRT). Expression of miR-15b in post-nRT tissue samples was associated with therapeutic outcome. DCLK1 was identified as the direct target gene for miR-15b and its suppression was associated with self-renewal and tumorigenic properties of DCLK1+ TICs. We identified B lymphoma Mo-MLV insertion region l homolog (BMI1) as a downstream target regulated by miR-15b/DCLK1 signaling. Thus, miR-15b may serve as a valuable marker for prognosis and therapeutic outcome prediction. DCLK1 could be a potential therapeutic target to overcome chemo-/radioresistance in CRC.

Somatic Mutations and Immune Alternation in Rectal Cancer Following Neoadjuvant Chemoradiotherapy.

Checkpoint blockade therapy triggers tumor-specific immune responses in a variety of cancer types. We presumed that rectal cancer patients could have become sensitive to immunotherapy after receiving neoadjuvant chemoradiotherapy (nCRT). In this study, we report immune alternation in post-nCRT patients compared with pretreatment conditions from gene-expression omnibus (GEO) data. Whole-exome sequencing of 14 locally advanced rectal cancer (LARC) patient samples showed that nCRT induced new mutations compared with the paired pretreatment biopsies, evidenced by appearance of a neoantigen landscape. An association was identified between mutation burden and enrichment of immune activation-related pathways. Animal experiment results further demonstrated that radiotherapy enhanced the efficacy of anti-PD-1. Mutation burden and the neoantigens of LARC patients were associated with response to nCRT. The mRNA expression profiling of 66 pretreatment biopsy samples from LARC patients showed that immune activation-related pathways were enriched in response to nCRT. PD-L1 expression was negatively correlated with disease-free survival in the CD8-low expression patient group who received nCRT in a cohort of 296 samples. Thus, nCRT was able to alter immune function in LARC patients, which may be associated with the appearance of neoantigens. Neoantigens could make rectal cancer patients potential candidates to receive checkpoint blockade immunotherapy, and mutation burden could be a useful biomarker to stratify patients into responding and nonresponding groups for immunotherapy. Cancer Immunol Res; 6(11); 1401-16. ©2018 AACR.

Serum-based microRNA signature predicts relapse and therapeutic outcome of adjuvant chemotherapy in colorectal cancer patients.

BACKGROUND: Approximately 60% of patients with colorectal cancer (CRC) undergo either local recurrence or distant metastases after surgery. Current prognostic biomarkers are insufficient to predict recurrence of CRC and provide little forecast information about what patients are likely to receive benefit from the adjuvant chemotherapy. As microRNAs (miRNAs) constantly exist in human serum and being used to predict the prognosis of a various cancers, this study was designed to identify miRNA-based circulating biomarkers to predict clinical outcomes of CRC. METHODS: A serum-focused miRNA expression was used to investigate if miRNA expression profiles could predict the clinical outcomes of patients with CRC. We created miRNA signature profiles associated in the training set (n = 40), and further validated its prediction in two independent testing cohorts. RESULTS: Using Cox regression and risk-score analysis, we identified a four-miRNA signature (miR-652-3p, miR-342-3p, miR-501-3p and miR-328-3p) for the prediction of tumor relapse and the overall survival(OS) of patients with CRC in the training set (n = 40). This miRNA signature was further validated in a testing set (n = 226) and another independent cohort (n = 56). A high-risk signature score was significantly associated with CRC tumor recurrence and poor treatment outcome. Multivariable Cox regression models indicated that the risk score, based on the four-miRNA signature, was an independent prognostic classifier for patients with CRC. CONCLUSIONS: The serum miRNA signature may serve as a minimally invasive predictor for tumor relapse and treatment outcome in patients with CRC and provide a useful reference for treatment selection.

Long non-coding RNA HOTAIR promotes cervical cancer progression through regulating BCL2 via targeting miR-143-3p.

BACKGROUND: HOX transcript antisense RNA (HOTAIR) is a long non-coding RNA (lncRNA) widely involved in the progression of numerous malignancies. Whereas, the potential molecular mechanism of HOTAIR involved in cervical cancer progression is still needed to be elaborated. METHODS: The expression of HOTAIR and miR-143-3p were detected in cervical cancer tissues and cells by qRT-PCR. MTT and flow cytometry analysis were performed to measure cell proliferation and apoptosis. Bioinformatics, Dual-Luciferase reporter and RIP were used to analyze the possible correlation between HOTAIR, miR-143-3p and BCL2. The expression of Bax and BCL2 was detected by western blot. Mice xenograft model was established to confirm the role of HOTAIR on tumor growth in vivo. RESULTS: HOTAIR expression was elevated while miR-143-3p expression was reduced in cervical cancer tissues and cell lines. HOTAIR knockdown suppressed proliferation and enhanced apoptosis in cervical cancer cells. Moreover, HOTAIR could function as a sponge for miR-143-3p. The inhibitory effect of HOTAIR knockdown on cervical cancer cells growth was abolished following decrease of miR-143-3p expression. Furthermore, HOTAIR promoted BCL2 expression by modulating miR-143-3p. BCL2 overexpression attenuated the tumor-suppressive effect of miR-143-3p in cervical cancer. Finally, the carcinogenicity of HOTAIR was validated in mice. CONCLUSIONS: HOTAIR promoted cervical cancer cell growth by modulating BCL2 via miR-143-3p, hinting a novel regulatory mechanism and potential therapeutic target in cervical cancer.

Prognostic value of pigment epithelium-derived factor for neoadjuvant radiation therapy in patients with locally advanced rectal carcinoma.

The aim of the study was to investigate the prognostic value of pigment epithelium-derived factor (PEDF) in locally advanced rectal carcinoma (LARC) treated with neoadjuvant radiation therapy (nRT). The level of PEDF expressing was examined in LARC tissues treated with nRT by immunohistochemistry and the prognostic significance of PEDF was analysed by univariate and multivariate survival analyses. We forced expression of PEDF in highly metastatic LoVo cells. The clonogenic survival assay was used to test the cellular sensitivity to radiation. Wound healing and Boyden chamber assays were used to detect cell migration and invasion. To assess the contribution of PEDF in vivo, we established tumor xenografts. The mechanisms of PEDF on cancer cells was analysed by bioinformatics. Our immunohistochemical staining of tissue samples revealed that prolonged DFS (77.1 vs 49.0%) and OS (87.1 vs 56.3%) was observed in PEDF-positive cases (P<0.001) following nRT. PEDF could be an independent factor for DFS [P=0.001; HR, 0.422 (95% CI, 0.249-0.717)] and OS [P=0.003; HR, 0.418 (95% CI, 0.234-0.749)]. Positive-expression of PEDF was negatively correlated with tumor differentiation (P<0.016), ypT stage (P<0.037), ypTNM stage (P<0.033), and ypN stage (P=0.006). Overexpression of PEDF in high metastatic cells enhanced radiosensitivity and, suppressed migration and invasion in vitro. In tumor xenografts, PEDF significantly suppressed tumor growth. Furthermore, by bioinformatics analysis, we found PEDF performs functions via activating P53 to regulate double-strand break repair pathway and activate the G protein activation pathway. Our findings indicate that PEDF was identified as a predictive candidate for nRT responsiveness. These findings may be used to stratify LARC patients and make alternative strategies for adjuvant treatment.

Nonexposure accurate location K-anonymity algorithm in LBS.

This paper tackles location privacy protection in current location-based services (LBS) where mobile users have to report their exact location information to an LBS provider in order to obtain their desired services. Location cloaking has been proposed and well studied to protect user privacy. It blurs the user's accurate coordinate and replaces it with a well-shaped cloaked region. However, to obtain such an anonymous spatial region (ASR), nearly all existent cloaking algorithms require knowing the accurate locations of all users. Therefore, location cloaking without exposing the user's accurate location to any party is urgently needed. In this paper, we present such two nonexposure accurate location cloaking algorithms. They are designed for K-anonymity, and cloaking is performed based on the identifications (IDs) of the grid areas which were reported by all the users, instead of directly on their accurate coordinates. Experimental results show that our algorithms are more secure than the existent cloaking algorithms, need not have all the users reporting their locations all the time, and can generate smaller ASR.