Weiting Ge

A distinct metabolic signature of human colorectal cancer with prognostic potential.

Purpose: Metabolic phenotyping has provided important biomarker findings, which, unfortunately, are rarely replicated across different sample sets due to the variations from different analytical and clinical protocols used in the studies. To date, very few metabolic hallmarks in a given cancer type have been confirmed and validated by use of a metabolomic approach and other clinical modalities. Here, we report a metabolomics study to identify potential metabolite biomarkers of colorectal cancer with potential theranostic value. Experimental Design: Gas chromatography–time-of-flight mass spectrometry (GC–TOFMS)–based metabolomics was used to analyze 376 surgical specimens, which were collected from four independent cohorts of patients with colorectal cancer at three hospitals located in China and City of Hope Comprehensive Cancer Center in the United States. Differential metabolites were identified and evaluated as potential prognostic markers. A targeted transcriptomic analysis of 29 colorectal cancer and 27 adjacent nontumor tissues was applied to analyze the gene expression levels for key enzymes associated with these shared metabolites. Results: A panel of 15 significantly altered metabolites was identified, which demonstrates the ability to predict the rate of recurrence and survival for patients after surgery and chemotherapy. The targeted transcriptomic analysis suggests that the differential expression of these metabolites is due to robust metabolic adaptations in cancer cells to increased oxidative stress as well as demand for energy, and macromolecular substrates for cell growth and proliferation. Conclusions: These patients with colorectal cancer, despite their varied genetic background, mutations, pathologic stages, and geographic locations, shared a metabolic signature that is of great prognostic and therapeutic potential. Clin Cancer Res; 20(8); 2136–46. ©2014 AACR.

Secreted Protein Acidic and Rich in Cysteines-like 1 Suppresses Aggressiveness and Predicts Better Survival in Colorectal Cancers

Purpose: Secreted protein acidic and rich in cysteines-like 1 (SPARCL1) is an extracellular matrix glycoprotein with malignancy-suppressing potential. The hypothesis that SPARCL1 reduces cancer invasiveness and predicts better survival in colorectal cancers (CRC) was investigated. Experimental Design: Stable SPARCL1 transfectants, RKO-SPARCL1, and corresponding vector control were constructed and implanted into nude mice to generate a mouse xenograft model of liver metastasis. Also, a retrospective outcome study was conducted on the COH set (222 CRCs) and ZJU set (412 CRCs). The protein expression level of SPARCL1 was determined by immunohistochemistry. The Kaplan–Meier and Cox analyses were used for survival analysis. The association of SPARCL1 with mesenchymal–epithelial transition (MET) was examined by reverse transcription PCR (RT-PCR) and Western blot analysis. Results: The ectopic expression of SPARCL1 significantly reduced the potential for anchorage-independent growth, migration, invasion and induced cell differentiation in RKO and SW620 cells. In mouse xenograft model, the expression of SPARCL1 significantly reduced the liver metastasis (P < 0.01). The patient-based studies revealed that the expression of SPARCL1 was related to better differentiation (P < 0.01), less lymph node involvement [OR, 0.67; 95% confidence interval (CI), 0.45–1.00], and less distant metastasis (OR, 0.38; 95% CI, 0.18–0.79). The Kaplan–Meier and Cox analysis showed that the expression of SPARCL1 was associated with better overall survival (log-rank: P < 0.01; HR, 0.57; 95% CI, 0.39–0.84). Transfection of SPARCL1 induced MET of colon cancer cells. Conclusion: SPARCL1 functions as a tumor suppressor promoting differentiation possibly via MET, which inhibits the aggressiveness of CRCs. Clin Cancer Res; 18(19); 5438–48. ©2012 AACR.

A seven-gene signature predicts overall survival of patients with colorectal cancer

Colorectal cancer (CRC) is a major cause of global cancer mortality. Gene expression profiles can help predict prognosis of patients with CRC. In most of previous studies, disease recurrence was analyzed as the survival endpoint. Thus we aim to build a robust gene signature for prediction of overall survival (OS) in patients with CRC. Fresh frozen CRC tissues from 64 patients were analyzed using Affymetrix HG-U133plus 2.0 gene arrays. By performing univariate survival analysis, 6487 genes were found to be associated with the OS in our cohort. KEGG analysis revealed that these genes were mainly involved in pathways such as endocytosis, axon guidance, spliceosome, Wnt signalling and ubiquitin mediated proteolysis. A seven-gene signature was further selected by a robust likelihood-based survival modelling approach. The prognostic model of seven-gene signature (NHLRC3, ZDHHC21, PRR14L, CCBL1, PTPRB, PNPO, and PPIP5K2) was constructed and weighted by regression coefficient, which divided patients into high- and low-risk groups. The OS for patients in high-risk group was significantly poorer compared with patients in low-risk group. Moreover, all seven genes were found to be differentially expressed in CRC tissues as compared with adjacent normal tissues, indicating their potential role in CRC initiation and progression. This seven-gene signature was further validated as an independent prognostic marker for OS prediction in patients with CRC in other two independent cohorts. In short, we developed a robust seven-gene signature that can predict the OS for CRC patients, providing new insights into identification of CRC patients with high risk of mortality.

EGFR Target Therapy Combined with Gemox for Advanced Biliary Tract Cancers: a Meta-analysis based on RCTs

Background: Controversy exists regarding whether EGFR-targeted therapy combined with GEMOX (gemcitabine and oxaliplatin) provides additional benefits over GEMOX alone for biliary tract cancer patients. Therefore, this meta-analysis of randomized controlled trials (RCTs) was performed to assess the efficacy and safety of the GEMOX + EGFR-targeted regimen, and subgroup analysis was conducted to identify groups that might benefit from targeted therapy. Methods: The PubMed, Cochrane Library, and ClinicalTrials.gov registries were searched for published studies. Hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS) were pooled using a fix-effect model. Risk-ratios (RRs) were used to analyse the objective response rate (ORR) and adverse events. Results: Four RCTs were assessed. GEMOX + EGFR-targeted therapy significantly improved PFS (HR = 0.80, 95% CI 0.66-0.94, P = 0.03) and was associated with a better ORR (RR = 1.52, 95% CI 1.13-2.04, P = <0.01), whereas the TKI group achieved a better ORR in subgroup analysis. Patients with cholangiocarcinoma responded well to the GEMOX + EGFR-targeted regimen, leading to a better ORR (RR = 1.78, 95% CI 1.21-2.61, P = <0.01). Unfortunately, PFS benefits were not translated into OS benefits (HR = 0.92, 95% CI 0.75-1.08, P = 0.39). Conclusion: GEMOX + EGFR-targeted therapy is a considerable and tolerable treatment option for patients with advanced BTCs, improving both PFS and ORR but not prolonging patient survival. Patients with cholangiocarcinoma would benefit the most from EGFR-targeted therapy.

Multi-omics Approach Reveals Distinct Differences in Left- and Right-Sided Colon Cancer

Increasing evidence suggests that left-sided colon cancer (LCC) and right-sided colon cancer (RCC) are emerging as two different colorectal cancer types with distinct clinical characteristics. However, the discrepancy in the underlying molecular event between these types of cancer has not been thoroughly elucidated to date and warrants comprehensive investigation. To this end, an integrated dataset from The Cancer Genome Atlas was used to compare and contrast LCC and RCC, covering mutation, DNA methylation, gene expression, and miRNA. Briefly, the signaling pathway cross-talk is more prevalent in RCC than LCC, such as RCC-specific PI3K pathway, which often exhibits cross-talk with the RAS and P53 pathways. Meanwhile, methylation signatures revealed that RCC was hypermethylated relative to LCC. In addition, differentially expressed genes (n = 253) and differentially expressed miRNAs (n = 16) were determined between LCC and RCC. Especially for Prostate Cancer Susceptibility Candidate 1 (PRAC1), a gene that was closely associated with hypermethylation, was the top significantly downregulated gene in RCC. Multi-omics comparison of LCC and RCC suggests that there are more aggressive markers in RCC and that tumor heterogeneity occurs within the location-based subtypes of colon cancer. These results clarify the debate regarding the conflicting prognosis between LCC and RCC, as proposed by different studies. Implications: The underlying molecular features present in LCC and RCC identified in this study are beneficial for adopting reasonable therapeutic approaches to prolong overall survival and progression-free survival in colorectal cancer patients. Mol Cancer Res; 16(3); 476–85. ©2017 AACR.

Abstract 706: Ribonucleotide reductase small subunit M2 is a potential prognostic biomarker in human epidermal growth factor receptor 2- positive and triple negative breast cancers

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Human epidermal growth factor receptor 2 (HER2)-positive breast cancer and triple negative breast cancer (TNBC) are two subtypes with poor outcome of all breast carcinomas. However, among all the patients in these two subtypes some still yielded relatively better prognosis. Ribonucleotide reductase (RR) small subunits M2 was associated with cancer cell invasiveness and metastasis, which prognoses poor survival in many cancers. Here we investigated whether RRM2 could serve as a prognostic biomarker for breast cancers, especially HER2- positive and TNBC subgroups. One hundred seventy five assessable breast cancers (40 cases were HER2-positive or TNBC) were collected from affiliated hospital of Zhejiang University (ZJU set); and six published microarray data sets (total 1154 cases, 63 cases were identified as HER2- positive or TNBC) with pathoclinical and follow- up information were employed for validation. In the ZJU set, the protein level of RRM2 was determined by IHC. It was indicated that RRM2 was positively correlated with cell proliferative marker Ki-67 (trends P=0.018) and stem/progenitor cell marker CD44+/CD24-/low (P=0.044). Multivariate COX model revealed that RRM2 was an independent prognostic biomarker for both OS (Hazard Ratio, HR=2.79, 95%Cl 1.21-6.75) and PFS (Hazard Ratio, HR=1.82, 95%Cl 1.02-3.26) for all the breast cancers. Moreover, in HER2-positive or TNBC breast cancers, RRM2-high was significantly associated with poor survival (P=0.025). Consequently, none of the patients with RRM2-low died of breast cancer in HER2-positive or TNBC subgroups. Furthermore, above findings were validated in the published data sets. The mRNA level of RRM2 evaluated significantly in highly-invasive subtypes including Luminal B, HER2-positive and TNBC in comparison with Luminal A and unclassified subgroups (P<0.05). Overexpression of RRM2 was positively associated with poor differentiation (P<0.05), advanced AJCC stage (P<0.05) as well as poor survival (P<0.05) in a dose-dependent manner. It was also revealed that high expression of RRM2 prognosed poor survival (HR=5.56, 95% CI 1.14-99.9) in HER2-positive breast cancers or TNBC. Moreover, the RRM2-high (protein or mRNA levels) was associated with better response to chemotherapy comparing to RRM2-low. Taken together, the above findings suggested that RRM2 was a potential biomarker for poor survival in breast cancer, especially in HER2- positive breast cancer and TNBC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 706. doi:1538-7445.AM2012-706

Abstract 2120: Secreted protein acidic and rich in cysteine, like 1(SPARCL1), inhibits aggressiveness and relates to better prognosis in colorectal cancers

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Secreted protein thats acidic and rich in cysteine, like 1(SPARCL1), an extracellular de-adhesion glycoprotein, was down-regulated in several solid cancers such as non-small cell lung cancer and pancreatic cancer. Our previous study revealed that expression of SPARCL1 was negatively related to liver metastasis of colorectal cancer (CRC). To clarify the function of SPARCL1 and its mechanism in CRC, the overexpression cell clone, RKO-SPARCL1, was created for illustrating biological behavior of SPARCL1 in vitro and in vivo. It was shown that SPARCL1 significantly reduced colony formation (p=0.027), invasion ability (p=0.001) and adhesion (p=0.04) of CRC cells in vitro. In comparison with vector control (RKO-pLXSN), RKO-SPARCL1 displayed significantly reduction in liver metastatic nodules in intrasplenic injection nude mice model (p=0.009). Meanwhile, tissue samples from 412 CRC patients were reassembled as tissue microarray for an outcome study. The antibody against SPARCL1 was developed for Immunohistochemistry (IHC) staining to assess the expression level of SPARCL1. Uni- and multivariate Logistic analysis demonstrated that SPARCL1 was negatively related with poorly tumor differentiation (p=0.001), lymph node metastasis (Odds ratio, OR=0.67, 95% 0.45-1.00) and distant metastasis (OR=0.39, 95% 0.18-0.82). The Kaplan-Meier analysis revealed that overexpression of SPARCL1 was significantly related to better overall survival in CRCs (p=0.004). Furthermore, the multivariate COX proportional hazard analysis demonstrated that SPARCL1 significantly reduced the risk of death from CRC (Hazard ratio, HR=0.57, 95% 0.39-0.84). Based on bioinformatics gene ontology analysis for gene expression microarray, overexpression of SPARCL1 significantly inhibited focal adhesion pathway and other tumor-associated oncogenes, such as S100A4 and ERBB3, in RKO cell line. Therefore, it is concluded that SPARCL1 may function as a tumor suppressor inhibiting the aggressiveness of cancer cells and reducing the risk of death from CRCs. It is suggested that SPARCL1 may serve as a prognostic biomarker for CRCs. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2120. doi:10.1158/1538-7445.AM2011-2120