Xinxiang Li

Downregulation of miR-193b contributes to enhance urokinase-type plasminogen activator (uPA) expression and tumor progression and invasion in human breast cancer

Emerging evidence suggests the potential involvement of altered regulation of miRNAs in the pathogenesis of cancers, and these miRNAs are thought to be functional as tumor suppressors or oncogenes. Using miRNA arrays, we identified an miRNA differentially expressed between the MDA-MB-231 cell line and its highly metastatic variant. A bioinformatics search revealed a potential target site for miR-193b within the 3′UTR of uPA. Ectopic expression of miR-193b repressed the expression of sensor constructs harboring the 3′UTR of uPA in breast cancer cell lines. Anti-miR-193b treatment led to an increase of uPA protein and increased cell invasion in MDA-MB-231 cells. In contrast, overexpression of miR-193b significantly reduced uPA protein amounts and inhibited cell invasion in MDA-MB-231 and MDA-MB-435 cells. In an immunodeficient mouse model, miR-193b significantly inhibited the growth and dissemination of xenograft tumors. Immunohistochemical staining and real-time PCR assays showed that miR-193b was a negative regulator of the uPA gene in primary breast tumors. Our research reveals that miR-193b is closely associated with clinical metastasis and identifies miR-193b potentially targets uPA transcripts. Perturbation of the miRNA–mRNA pairing may have important roles in the initiation and development of breast cancer.

TPX2 is a novel prognostic marker for the growth and metastasis of colon cancer

BackgroundWe have previously demonstrated an aberrant overexpression of the microtubule-associated protein TPX2 in colon cancer using a genome-wide gene expression profiling analysis. Here, we aim to investigate its expression pattern, clinical significance, and biological function in colon cancer.MethodsTPX2 expression was analyzed in human colon cancer cell lines and tumor samples. The effect of TPX2 on cell proliferation, tumorigenesis, and metastasis was examined in vitro and in vivo.ResultsTPX2 was overexpressed in 129 of the 203 (60.8%) colon cancer metastatic lesions, with the expression being significantly higher than that in primary cancerous tissue and normal colon mucosa. Overexpression of TPX2 was significantly associated with clinical staging, vessel invasion, and metastasis. In survival analyses, patients with TPX2 overexpression had worse overall survival and metastasis free survival, suggesting that deregulation of TPX2 may contribute to the metastasis of colon cancer. Consistent with this, suppression of TPX2 expression inhibited proliferation and tumorigenicity of colon cancer cells both in vitro and in vivo. Strikingly, we found that TPX2 knockdown significantly attenuated the migration and invasion ability of colon cancer cells, which was further shown to be mechanistically associated with AKT-mediated MMP2 activity.ConclusionsThese findings suggest that TPX2 plays an important role in promoting tumorigenesis and metastasis of human colon cancer, and may represent a novel prognostic biomarker and therapeutic target for the disease.

Nomograms for predicting prognostic value of inflammatory biomarkers in colorectal cancer patients after radical resection

Increasing evidence indicates that inflammation plays a vital role in tumorigenesis and progression. However, the prognostic value of inflammatory biomarkers in colorectal cancer (CRC) has not been established. In this study, a retrospective analysis was conducted in patients with CRC in Fudan University Shanghai Cancer Center (FUSCC) between April 1, 2007 and April 30, 2014, and 5,336 patients were identified eligible. Neutrophil‐to‐lymphocyte ratio (NLR), platelet‐to‐lymphocyte ratio (PLR), lymphocyte‐to‐monocyte ratio (LMR), and albumin/globulin ratio (AGR) were analyzed. Kaplan‐Meier analysis was used to calculate the 5‐year overall survival (OS) and disease‐free survival (DFS). Cox regression analysis was performed to assess the prognostic factors. Nomograms were established to predict OS and DFS, and Harrells concordance index (c‐index) was adopted to evaluate prediction accuracy. As results, the 5‐year OS was 79.2% and the 5‐year DFS was 56.0% in the cohort. Patients were stratified into 2 groups by NLR (≤2.72 and >2.72), PLR (≤219.00 and >219.00), LMR (≤2.83 and >2.83) and AGR (<1.50 and ≥1.50). Patients with NLR > 2.72, PLR > 219.00, LMR ≤ 2.83 and AGR < 1.50 were significantly associated with decreased OS and DFS (p < 0.001). Multivariate analysis indicated that NLR, LMR and AGR were independent factors of OS (p = 0.047, p = 0.008 and p < 0.001, respectively) and DFS (p = 0.009, p < 0.001 and p = 0.008, respectively). In addition, nomograms on OS and DFS were established according to all significant factors, and c‐indexes were 0.765 (95% CI: 0.744–0.785) and 0.735 (95% CI: 0.721–0.749), respectively. Nomograms based on OS and DFS can be recommended as practical models to evaluate prognosis for CRC patients.

Sirt3 binds to and deacetylates mitochondrial pyruvate carrier 1 to enhance its activity.

Mitochondrial pyruvate carrier (MPC), composed of MPC1 and MPC2, can modulate pyruvate oxidation in mitochondrial and MPC1 expression correlates with poor prognosis of multiple cancers. Here, we reported that MPC1 is acetylated and its main acetylation sites are: K45 and K46. Sirt3 binds to and deacetylates MPC1. High glucose decreases MPC1 acetylation level by increasing Sirt3-MPC1 binding. Furthermore, acetylation mimic mutation of MPC1 reduces it activity and abolishes its function in inhibition of colon cancer cell growth. These results reveal a novel post-translational regulation of MPC1 by Sirt3, which is important for its activity and colon cancer cell growth.

Prognostic Nomograms for Predicting Survival and Distant Metastases in Locally Advanced Rectal Cancers

Aim To develop prognostic nomograms for predicting outcomes in patients with locally advanced rectal cancers who do not receive preoperative treatment. Materials and Methods A total of 883 patients with stage II–III rectal cancers were retrospectively collected from a single institution. Survival analyses were performed to assess each variable for overall survival (OS), local recurrence (LR) and distant metastases (DM). Cox models were performed to develop a predictive model for each endpoint. The performance of model prediction was validated by cross validation and on an independent group of patients. Results The 5-year LR, DM and OS rates were 22.3%, 32.7% and 63.8%, respectively. Two prognostic nomograms were successfully developed to predict 5-year OS and DM-free survival rates, with c-index of 0.70 (95% CI = [0.66, 0.73]) and 0.68 (95% CI = [0.64, 0.72]) on the original dataset, and 0.76 (95% CI = [0.67, 0.86]) and 0.73 (95% CI = [0.63, 0.83]) on the validation dataset, respectively. Factors in our models included age, gender, carcinoembryonic antigen value, tumor location, T stage, N stage, metastatic lymph nodes ratio, adjuvant chemotherapy and chemoradiotherapy. Predicted by our nomogram, substantial variability in terms of 5-year OS and DM-free survival was observed within each TNM stage category. Conclusions The prognostic nomograms integrated demographic and clinicopathological factors to account for tumor and patient heterogeneity, and thereby provided a more individualized outcome prognostication. Our individualized prediction nomograms could help patients with preoperatively under-staged rectal cancer about their postoperative treatment strategies and follow-up protocols.

Predictive value of pretreatment lymphocyte count in stage II colorectal cancer and in high-risk patients treated with adjuvant chemotherapy

Pretreatment lymphocyte count (LC) has been associated with prognosis and chemotherapy response in several cancers. The predictive value of LC for stage II colorectal cancer (CRC) and for high-risk patients treated with adjuvant chemotherapy (AC) has not been determined. A retrospective review of prospectively collected data from 1332 consecutive stage II CRC patients who underwent curative tumor resection was conducted. A pretreatment LC value <1.3 Giga/L(28.1%, 373/1332) was defined as low LC. A total of 738 patients (55.4%) were considered high-risk, 459 (62.2%) of whom received AC. Patients with low LCs had significantly worse 5-year OS (74.6% vs. 90.2%, p < 0.001) and DFS (61.3% vs. 84.6%, p < 0.001). High-risk patients with low LCs had the poorest DFS (p < 0.001). Multivariate analysis indicated that low LC value or combined with high-risk status were both independent prognostic factors(p <0.001). High-risk, AC-treated patients with high LCs had significantly longer DFS than untreated patients (HR, 0.594; 95% CI, 0.364–0.970; p = 0.035). There was no difference or trend for DFS or OS in patients with low LCs, regardless of the use of AC (DFS, p = 0.692; OS, p = 0.522). Low LC was also independently associated with poorer DFS in high-risk, AC-treated patients (HR, 1.885; 95% CI, 1.112–3.196; p = 0.019). CONCLUSIONS: Pretreatment LC is an independent prognostic factor for survival in stage II CRC. Furthermore, pretreatment LC reliably predicts chemotherapeutic efficacy in high-risk patients with stage II CRC.

Gas1 Inhibits Metastatic and Metabolic Phenotypes in Colorectal Carcinoma.

Growth arrest–specific 1 (Gas1) plays a critical role in growth suppression. Previous study indicated that Gas1 was closely associated with survival in patients with colorectal cancer; however, the underlying molecular mechanism remains unclear. In this study, we sought to determine the role of Gas1 in tumorigenesis and metastasis, and elucidate the possible mechanism. First, Gas1 was determined as a negative regulator of oncogenesis and metastasis in colorectal cancer. Mechanistically, Gas1 negatively regulated the aerobic glycolysis, a process that contributed to tumor progression and metastasis by providing energy source and building blocks for macromolecule synthesis. To further consolidate the role of Gas1 in glycolysis, the impact of Gas1 in the transcription of key glycolytic enzymes for glucose utilization was examined. As expected, GLUT4, HK2, and LDHB exhibited a decreased expression pattern. Consistent with this observation, an in vivo subcutaneous xenograft mouse model also confirmed the hypothesis that Gas1 is a negative regulator of glycolysis as reflected by the decreased 18FDG uptake in PET/CT system. Moreover, Gas1 negatively regulated the AMPK/mTOR/p70S6K signaling axis, a well-established cascade that regulates malignant cancer cell behaviors including proliferation, metastasis, and aberrant cancer metabolism. In the end, it was determined that Gas1 is a transcriptional target of FOXM1, whose role in colorectal cancer has been widely studied. Taken together, these studies establish Gas1 as a negative regulator in colorectal cancer. Implications: Gas1 suppresses cell proliferation, invasion, and aerobic glycolysis of colorectal cancer both in vitro and in vivo. Mechanistically, Gas1 inhibited EMT and the Warburg effect via AMPK/mTOR/p70S6K signaling, and Gas1 itself was directly regulated by the transcription factor FOXM1. Mol Cancer Res; 14(9); 830–40. ©2016 AACR.

High expression of protein phosphatase 4 is associated with the aggressive malignant behavior of colorectal carcinoma

BackgroundRecent evidence suggests an important role of protein phosphatase 4 (PP4C) in the progression of several cancers, including breast cancer, lung cancer and pancreatic ductal adenocarcinoma. However, the contribution of PP4C to colorectal carcinoma (CRC) remains elusive.MethodsThe expression of PP4C in CRC tissues compared with matched non-tumor tissues and CRC cells was detected using quantitative RT-PCR, immunohistochemistry and western blotting assays. Through univariate and Kaplan-Meier analysis, we correlated the PP4C expression with clinicopathological features and patient survival. A series of experiments, including cell proliferation, lentiviral infection, cell invasion and MMP gelatinase activity assays, were performed to investigate the underlying mechanisms. Through further experiments, tumor growth and metastasis were evaluated in vivo using a xenogenous subcutaneously implant model and a tail vein metastasis model.ResultsIn the present study, we found that PP4C expression is frequently increased in human CRC and that the upregulation of PP4C correlates with a more invasive tumor phenotype and poor prognosis. The ectopic expression of PP4C promoted CRC cell proliferation, migration and invasion in vitro and tumor growth and lung metastasis in vivo. Silencing the expression of PP4C resulted in the inhibition of cell proliferation and invasion. Further investigations showed that phosphorylated Akt (p-AKT) is required for the PP4C-mediated upregulation of MMP-2 and MMP-9, which promotes cell invasion.ConclusionsOur data suggested a potential role of PP4C in tumor progression and provided novel insights into the mechanism of how this factor positively regulated cell proliferation and invasion in CRC cells.

Aldolase B overexpression is associated with poor prognosis and promotes tumor progression by epithelial-mesenchymal transition in colorectal adenocarcinoma

Background: Glycolysis is considered to be the root of cancer development and progression, which involved a multi-step enzymatic reaction. Our study aimed at figuring out which glycolysis enzyme participates in the development of colorectal cancer and its possible mechanisms. Methods: We firstly screened out Aldolase B (ALDOB) by performing qRT-PCR arrays of glycolysis-related genes in five paired liver metastasis and primary colorectal tissues, and further detected ALDOB protein with immunohistochemistry in tissue microarray (TMA) consisting of 229 samples from stage I-III colorectal cancer patients. CRISPR-Cas9 method was adopted to create knock out colon cancer cell lines (LoVo and SW480) of ALDOB. The effect of ALDOB on cell proliferation and metastasis was examined in vitro using colony formation assay as well as transwell migration and invasion assay, respectively. Results: In TMA, there was 64.6% of samples demonstrated strong intensity of ALDOB. High ALDOB expression were associated with poor overall survival and disease-free survival in both univariate and multivariate regression analyses (P<0.05). In vitro functional studies of CCK-8 demonstrated that silencing ALDOB expression significantly (P<0.05) inhibited proliferation, migration and invasion of colon cancer cells. Mechanically, silencing ALDOB activated epithelial markers and repressed mesenchymal markers, indicating inactivation of ALDOB may lead to inhibition of epithelial-mesenchymal transition (EMT). Conclusion: Upregulation of ALDOB promotes colorectal cancer metastasis by facilitating EMT and acts as a potential prognostic factor and therapeutic target in colorectal cancer.

Effect of Lymph Node Count on Pathological Stage III Rectal Cancer with Preoperative Radiotherapy.

Lymph node (LN) status after surgery for rectal cancer is affected by preoperative radiotherapy. The purpose of this study was to perform a population-based evaluation of the impact of pathologic LN status after neoadjuvant radiotherapy on survival. A total of 1,650 patients receiving neoadjuvant chemotherapy in Surveillance, Epidemiology, and End Results Program (SEER)-registered ypIII stage rectal cancer was analyzed. We identified the optimal cutoff for retrieved LNs as 10 (χ2 = 14.006, P < 0.001), which was validated as an independent prognosis factors in a Cox regression model. Further analysis showed that the LN count was only a prognosis factor with the number from 8 to 16(except for 13).After the number 16, the 5-year survival rate decreased gradually. Collectively, our results confirmed that the number of LNs in yp III stage rectal patients was a prognosis factor only with the numbers from 8 to 16(except for 13). Using the total mesorectal excision technique with an adequate pathologic examination, a large number of LNs retrieved (≥17) might indicate worse tumor response grade and poorer survival.