Xianhua Gao

Red and processed meat intake and risk of colorectal adenomas: A meta‐analysis of observational studies

Inconsistent results regarding the association between red and processed meat intake and the risk of colorectal adenoma (CRA), the precursor of colorectal cancer (CRC), have been reported. To provide a quantitative assessment of this association, we summarized the evidence from observational studies. Relevant studies were identified in MEDLINE and EMBASE until December 31, 2011. Summary relative risks (SRRs) with 95% confidence intervals (CIs) were pooled with a random‐effects model. Between‐study heterogeneity was assessed using the Cochrans Q and I2 statistics. A total of 21 studies (16 case–control studies and five cohort/nested case–control studies) were included in this meta‐analysis. The SRRs of CRA were 1.36 (95% CI = 1.17–1.58) for every 100 g/day increase in red meat intake, and 1.24 (95% CI = 1.12–1.36) for the highest versus the lowest level of red meat intake. Nonlinear dose‐response meta‐analysis indicated that CRA risk increased approximately linearly with increasing intake of red meat up to ∼ 90 g/day, where the curve reached its plateau. Subgrouped analyses revealed that the increased risk of CRA with intake of red meat was independent of geographic locations, design and confounders. The SRRs of CRA was 1.28 (95% CI = 1.03–1.60) for per 50 g/day increase in processed meat intake, and 1.17 (95% CI = 1.08–1.26) for the highest versus the lowest level of processed meat intake. Increased intake of red and processed meat is associated with significantly increased risk of CRA.

Dietary intake of vitamins A, C, and E and the risk of colorectal adenoma: a meta-analysis of observational studies.

To comprehensively summarize the association between dietary intake of vitamins A, C, and E and the risk of colorectal adenoma (CRA), the precursor of colorectal cancer, relevant studies were identified in MEDLINE and EMBASE up to 31 October 2012. Summary relative risks (SRRs) with 95% confidence intervals (CIs) were pooled with a random-effects model. Between-study heterogeneity was assessed using Cochran’s Q and I2 statistics. A total of 13 studies with 3832 CRA cases were included in this meta-analysis. On the basis of the highest versus lowest analysis, dietary intake of vitamin C reduced the risk of CRA by 22% (SRRs 0.78, 95% CIs: 0.62–0.98). Subgroup analyses showed that this relation was not modified by BMI, smoking status, and dietary energy intake. Further, dietary intake of &bgr;-carotene was also inversely associated with the risk of CRA. However, dietary intake of vitamins A and E was not associated with the risk of CRA in overall and subgroup analyses (vitamin A: SRRs 0.87, 95% CIs: 0.67–1.14; vitamin E: SRRs 0.87, 95% CIs: 0.69–1.10). Our results indicate that dietary intake of vitamin C and &bgr;-carotene, but not vitamins A and E, could reduce the risk of CRA. However, these associations seem to be limited. Further investigation using large samples and a rigorous methodology is warranted.

Gene expression profiling-derived immunohistochemistry signature with high prognostic value in colorectal carcinoma

Objective Gene expression profiling provides an opportunity to develop robust prognostic markers of colorectal carcinoma (CRC). However, the markers have not been applied for clinical decision making. We aimed to develop an immunohistochemistry signature using microarray data for predicting CRC prognosis. Design We evaluated 25 CRC gene signatures in independent microarray datasets with prognosis information and constructed a subnetwork using signatures with high concordance and repeatable prognostic values. Tumours were examined immunohistochemically for the expression of network-centric and the top overlapping molecules. Prognostic values were assessed in 682 patients from Shanghai, China (training cohort) and validated in 343 patients from Guangzhou, China (validation cohort). Median follow-up duration was 58 months. All p values are two-sided. Results Five signatures were selected to construct a subnetwork. The expression of GRB2, PTPN11, ITGB1 and POSTN in cancer cells, each significantly associated with disease-free survival, were selected to construct an immunohistochemistry signature. Patients were dichotomised into high-risk and low-risk subgroups with an optimal risk score (1.55). Compared with low-risk patients, high-risk patients had shorter disease-specific survival (DSS) in the training (HR=6.62; 95% CI 3.70 to 11.85) and validation cohorts (HR=3.53; 95% CI 2.13 to 5.84) in multivariate Cox analyses. The signature better predicted DSS than did tumour-node-metastasis staging in both cohorts. In those who received postoperative chemotherapy, high-risk score predicted shorter DSS in the training (HR=6.35; 95% CI 3.55 to 11.36) and validation cohorts (HR=5.56; 95% CI 2.25 to 13.71). Conclusions Our immunohistochemistry signature may be clinically practical for personalised prediction of CRC prognosis.

Periostin expression in intra-tumoral stromal cells is prognostic and predictive for colorectal carcinoma via creating a cancer-supportive niche

Periostin (POSTN) expression in cancer cells and circulation has been related to poor prognosis of colorectal carcinoma (CRC). However, the role of POSTN expressed in intra-tumoral stroma on CRC progression remains largely unknown. This study enrolled 1098 CRC patients who received surgical treatment in Shanghai and Guangzhou, Mainland China. In Shanghai cohort, immunohistochemistry score of stromal POSTN expression increased consecutively from adjacent mucosa, primary CRC tissues, to metastatic CRC tissues (P < 0.001), while medium- and high-stromal POSTN expression, rather than epithelial POSTN expression, independently predicted unfavorable prognoses of CRC, adjusted for covariates including TNM stage and postoperative chemotherapy in multivariate Cox models. The results in Shanghai cohort were faithfully replicated in Guangzhou cohort. Stromal POSTN expression dose-dependently predicted an unfavorable prognosis of stage III CRC patients with postoperative chemotherapy in both cohorts. POSTN derived from colonic fibroblasts or recombinant POSTN significantly promoted proliferation, anchorage independent growth, invasion, and chemo-resistance of CRC cells; whereas these effects were counteracted via targeting to PI3K/Akt or Wnt/β-catenin signaling pathway. CRC cell RKO-derived factor(s) significantly induced POSTN production in colonic fibroblasts and autocrine POSTN promoted proliferation, migration, and anchorage independent growth of fibroblasts. Conclusively, stromal POSTN is prognostic and predictive for CRC via creating a niche to facilitate cancer progression. Targeting POSTN-induced signaling pathways may be therapeutic options for metastatic or chemoresistant CRC.

Upregulation of nemo-like kinase is an independent prognostic factor in colorectal cancer

AIM To investigate the expression and oncogenic role of nemo-like kinase (NLK) in colorectal cancer. METHODS Expression of NLK protein was assessed by immunohistochemistry in tissue specimens from 56 cases of normal colorectal mucosa, 51 cases of colorectal adenoma, and 712 cases of colorectal cancer. In addition, NLK expression was knocked down using a lentivirus carrying NLK small hairpin RNA in colorectal cancer cells. Cell viability methylthiazoletetrazolium assays, colony formation assays, flow cytometry cell cycle assays, Transwell migration assays, and gene expression assays were performed to explore its role on proliferation and migration of colorectal cancer. RESULTS Expression of NLK protein progressively increased in tissues from the normal mucosa through adenoma to various stages of colorectal cancer. Overexpression of NLK protein was associated with advanced tumor-lymph node-metastasis stages, poor differentiation, lymph node and distant metastases, and a higher recurrence rate of colorectal cancer (P < 0.05). Multivariate analyses showed that NLK expression was an independent prognostic factor to predict overall survival (hazard ratio 2.57, 95% confidence interval: 1.66-3.98; P < 0.001) and disease-free survival (hazard ratio 1.96, 95% confidence interval: 1.40-2.74: P < 0.001) of colorectal cancer patients. Furthermore, knockdown of NLK expression in colorectal cancer cell lines reduced cell viability, colony formation, and migration, and arrested tumor cells at the G0/G1 phase of the cell cycle. At the gene level, knockdown of NLK expression inhibited matrix metalloproteinase-2 expression in colorectal cancer cells. CONCLUSION NLK overexpression is an independent prognostic factor in colorectal cancer and knockdown of NLK expression inhibits colorectal cancer progression and metastasis.

Downregulation of ATP-binding cassette subfamily C member 4 increases sensitivity to neoadjuvant radiotherapy for locally advanced rectal carcinoma.

OBJECTIVE: This study was designed to verify the effect of ATP-binding cassette subfamily C member 4 on radiosensitivity of locally advanced rectal carcinoma. SETTING: The expression of ATP-binding cassette subfamily C member 4 protein in 121 pretreatment tissue samples from locally advanced rectal carcinoma patients was detected by immunohistochemistry. DESIGN: Pathological response to radiotherapy was evaluated according to tumor regression grading by postoperative histological examinations after they received long-course preoperative neoadjuvant radiotherapy, and the association between clinicopathological data and tumor regression grading was analyzed retrospectively. For further validation, short hairpin RNA was constructed and transfected into colorectal carcinoma cell line HT29. The knockdown efficiency was confirmed at both RNA and protein levels. The altered radiosensitivity was evaluated by methylthiazolyl tetrazolium assay, colony formation assay, flow cytometry, and Hoechst 33258 staining. RESULTS: Univariate analysis revealed that ATP-binding cassette subfamily C member 4 expression (p < 0.001), P53 type (p = 0.069), and CEA (p = 0.100) were possibly associated with tumor regression grading, and multivariate analysis demonstrated that ATP-binding cassette subfamily C member 4 expression (p < 0.001) and P53 type (p = 0.039) were positively correlated with response to neoadjuvant radiotherapy in locally advanced rectal carcinoma patients. Lentiviral vector was successfully introduced into HT29 cells and inhibited ATP-binding cassette subfamily C member 4 expression efficiently and persistently. Downregulation of ATP-binding cassette subfamily C member 4 expression significantly enhanced inhibition of cell proliferation, decreased colony formation capacity, and increased cell apoptosis induced by irradiation, as examined by a series of experiments in vitro. In addition, radiobiological parameters calculated according to the single-hit multitarget model were also decreased significantly. CONCLUSIONS: Our data indicate that ATP-binding cassette subfamily C member 4 may be a useful molecular marker in predicting radiosensitivity, and a potential target in improving the response to neoadjuvant radiotherapy in locally advanced rectal carcinoma patients.

Prognostic significance and molecular mechanism of ATP-binding cassette subfamily C member 4 in resistance to neoadjuvant radiotherapy of locally advanced rectal carcinoma.

Background Mechanism of radioresistance in rectal carcinoma remains largely unknown. We aimed to evaluate the predictive role of ATP-binding cassette subfamily C member 4 (ABCC4) in locally advanced rectal carcinoma and explore possible molecular mechanisms by which ABCC4 confers the resistance to neoadjuvant radiotherapy. Methods The expression of ABCC4 and P53 mutant in biopsy tissue specimens from 121 locally advanced rectal carcinoma patients was examined using immunohistochemistry. The factors contributing to 3-year overall survival and disease-free survival were evaluated using the Kaplan-Meier method and Cox proportional hazard model. Lentivirus-mediated small hairpin RNA was applied to inhibit ABCC4 expression in colorectal carcinoma cell line RKO, and investigate the radiosensitivity in xenograft model. Intracellular cyclic adenosine monophosphate concentration and cell cycle distribution following irradiation were detected. Results High expression of ABCC4 and p53 mutant in pretreated tumors, poor pathological response, and high final tumor staging were significant factors independently predicted an unfavorable prognosis of locally advanced rectal carcinoma patients after neoadjuvant radiotherapy. Down-regulation of ABCC4 expression significantly enhanced irradiation-induced suppression of tumor growth in xenograft model. Furthermore, down-regulation of ABCC4 expression enhanced intracellular cyclic adenosine monophosphate production and noticeable deficiency of G1-S phase checkpoint in cell cycle following irradiation. Conclusions Our study suggests that ABCC4 serves as a novel predictive biomarker that is responsible for the radioresistance and predicts a poor prognosis for locally advanced rectal carcinoma after neoadjuvant radiotherapy.

Abstract C217: Prognostic significance and molecular mechanism of ATP-Binding Cassette subfamily C member 4 in resistance to neoadjuvant radiotherapy of locally advanced rectal carcinoma.

Mechanism of radioresistance in rectal carcinoma remains largely unknown. The aim of this study is to verify the predictive value of ATP-Binding Cassette subfamily C member 4 (ABCC4) in locally advanced rectal carcinoma and explore possible molecular mechanisms by which ABCC4 confers the resistance to neoadjuvant radiotherapy. Methods: Expression of ABCC4 protein in pretreated biopsy tissue specimens from locally advanced rectal carcinoma patients was examined using immunohistochemistry. The 3-year overall survival and disease-free survival were used to determine long-term prognosis, and significant clinicopathological factors were identified by univariate log-rank test and multivariate Cox regression analysis. Lentivirus-mediated small hairpin RNA inhibited ABCC4 expression in colorectal carcinoma cell lines, and altered radiosensitivity was confirmed by xenograft model in vivo. Intracellular cyclic adenosine monophosphate concentration and cell cycle distribution following irradiation were further detected. Results: High expression of ABCC4 in pretreated tumors, p53 mutant type, high serum CEA and positive lymph node predicted an unfavorable postoperative prognosis for locally advanced rectal carcinoma patients after neoadjuvant radiotherapy in univariate analysis. Multivariate Cox regression analysis further demonstrated that high expression of ABCC4 and p53 mutant type were significant factors independently predicted an unfavorable long-term prognosis. Downregulation of ABCC4 expression significantly enhanced irradiation-induced suppression of tumor growth in xenograft model in vivo. Furthermore, inhibition of ABCC4 expression induced intracellular cyclic adenosine monophosphate accumulation and a noticeable deficiency of G1-S phase checkpoint in cell cycle following irradiation. Conclusions: Our study suggests ABCC4 as a novel predictive biomarker in predicting radioresistance and prognosis for locally advanced rectal carcinoma. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C217. Citation Format: Zhiqi Yu, Chang Zhang, Rui Chai, Yan Du, Xianhua Gao, Junjie Xing, Guangwen Cao, Chuangang Fu. Prognostic significance and molecular mechanism of ATP-Binding Cassette subfamily C member 4 in resistance to neoadjuvant radiotherapy of locally advanced rectal carcinoma. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C217.

Abstract B35: Aberrant expression of ABCC3 in rectal cancer predicts poor prognosis and pathological response to neoadjuvant chemoradiotherapy via activating the caspase-3 dependent apoptotic pathway

Objective: To clarify the role of ATP binding cassette subfamily C member 3 (ABCC3) on prognosis and pathological response to neoadjuvant chemoradiotherapy in rectal cancer, and further explore the potential molecular mechanism. Design: Retrospective analysis of clinicopathologic factors and detection of ABCC3 expression in pretreatment biopsy specimens from 144 cases of stage II–III rectal cancer who received neoadjuvant chemoradiotherapy and radical surgery. Pathological response according to tumor regression grade and long-term survival curve were further determined. ABCC3 expression was down-regulated using short interfering RNA in colorectal carcinoma cells HT-29 and SW-480. Cell proliferation and apoptosis in response to 5-fluorouracil or irradiation were examined using colony formation assay, single-hit multi-target model, flow cytometry and Hoechst 33342 staining, respectively. Tumor growth following fractional irradiation was measured in xenograft mouse model. Change of intracellular reactive oxygen species contents and activation of cleaved caspase-3 expression were further explored. Results: Aberrant expression of ABCC3 was an independent factor significantly predicting poor pathological response to neoadjuvant chemoradiotherapy (P=0.002) and prognosis (3-year Overall Survival: P=0.011; 3-year Disease-free Survival: P=0.003). Down-regulation of ABCC3 expression significantly increased 5-fluorouracil or irradiation induced cell apoptosis in vitro, and tumor growth was significantly suppressed following irradiations in vivo. Furthermore, inhibition of ABCC3 expression obviously activated caspase-3 dependent apoptotic pathway and decreased intracellular reactive oxygen species exporting from cells after being exposed to irradiations. Conclusion: ABCC3 is an attractive target for improving sensitivity to neoadjuvant chemoradiotherapy and of potential value for a clinical breakthrough in the comprehensive treatment of rectal cancer patients. Note:This abstract was not presented at the conference. Citation Format: Zhiqi Yu, Chang Zhang, Xianhua Gao, Junjie Xing, Hao Wang, Enda Yu, Wei Zhang, Xiaoqing Zhang, Guangwen Cao, Chuangang Fu. Aberrant expression of ABCC3 in rectal cancer predicts poor prognosis and pathological response to neoadjuvant chemoradiotherapy via activating the caspase-3 dependent apoptotic pathway. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr B35.