Yuting Kuang

Salinomycin induces apoptosis in cisplatin-resistant colorectal cancer cells by accumulation of reactive oxygen species

Postoperative chemotherapy for Colorectal cancer (CRC) patients is not all effective and the main reason might lie in cancer stem cells (CSCs). Emerging studies showed that CSCs overexpress some drug-resistance related proteins, which efficiently transport the chemotherapeutics out of cancer cells. Salinomycin, which considered as a novel and an effective anticancer drug, is found to have the ability to kill both CSCs and therapy-resistant cancer cells. To explore the potential mechanisms that salinomycin could specifically target on therapy-resistant cancer cells in colorectal cancers, we firstly obtained cisplatin-resistant (Cisp-resistant) SW620 cells by repeated exposure to 5 μmol/l of cisplatin from an original colorectal cancer cell line. These Cisp-resistant SW620 cells, which maintained a relative quiescent state (G0/G1 arrest) and displayed stem-like signatures (up-regulations of Sox2, Oct4, Nanog, Klf4, Hes1, CD24, CD26, CD44, CD133, CD166, Lgr5, ALDH1A1 and ALDH1A3 mRNA expressions) (p < 0.05), were sensitive to salinomycin (p < 0.05). Salinomycin did not show the influence on the cell cycle of Cisp-resistant SW620 cells (p > 0.05), but could induce cell death process (p < 0.05), with increased levels of LDH release and MDA contents as well as down-regulations of SOD and GSH-PX activities (p < 0.05). Our data also showed that the pro-apoptotic genes (Caspase-3, Caspase-8, Caspase-9 and Bax) were up-regulated and the anti-apoptotic gene Bcl-2 were down-regulated in Cisp-resistant SW620 cells (p < 0.05). Accumulated reactive oxygen species and dysregulation of some apoptosis-related genes might ultimately lead to apoptosis in Cisp-resistant SW620 cells. These findings will provide new clues for novel and selective chemotherapy on cisplatin-resistant colorectal cancer cells.

Metastasis-related miR-185 is a potential prognostic biomarker for hepatocellular carcinoma in early stage.

We previously reported that miR-185 is associated with hepatocellular carcinoma (HCC) venous metastasis analysed by miRNA-array profile. The aim of this study is to further investigate the clinicopathological significance and prognostic value of miR-185 in early stage HCC. We classified 95 patients with early stage HCC into treated recurrence group (TR) and none treated recurrence group (NTR), and detected the miR-185 expression levels in TR and NTR groups. We found that low miR-185 expression correlated with more tumor recurrence (37/46), while high miR-185 level led to lower recurrence rate (17/49) (P<0.05). There was no direct relationship between miR-185 and clinicopathological features, including age, gender, ALT, AFP, liver cirrhosis, tumor size, tumor encapsulation, tumor differentiation (P>0.05). Kaplan-Meier analysis showed that low miR-185 group had a remarkable lower survival rate and shorter time to recurrence than high miR-185 group (P<0.05). Univariate and multivariate analysis, using Coxs proportional hazards model, also indicated that low miR-185 expression was a sensitive prognostic factor for survival and recurrence in early stage HCC (P<0.05). We upregulated or downregulated miR-185 expression by transfected miR-185 mimics or inhibitor into HCC cell lines, and observed the influence of miR-185 on HCC cells in vitro. Our results manifested that miR-185 could suppress the tumor cell growth and invasive ability (P<0.05). Therefore, miR-185 might be an effective and sensitive biomarker of HCC in early stage, and the upregulation of miR-185 might be considered to be a potentially important molecular treatment strategy for patients with HCC.

The coexpression and clinical significance of costimulatory molecules B7-H1, B7-H3, and B7-H4 in human pancreatic cancer

Aim We investigated the expression of the inhibitory costimulatory molecules B7-H1, B7-H3, and B7-H4 in human pancreatic cancer to define their clinical significance and mechanism in a tumor microenvironment. Patients and methods Sixty-three pancreatic cancer tissues and 12 normal pancreatic tissues were examined in our research. Patients were enrolled in the study between December 2000 and August 2010. Expression levels of the B7 family of molecules and densities of tumor-infiltrating lymphocytes in the tissues were characterized with immunohistochemical assays. Results More than 50% of the patients expressed B7-H1 and B7-H4, and nearly 100% of the patients expressed B7-H3. B7-H1 expression was correlated with tumor size, B7-H3 expression was correlated with lymph-node metastasis and differentiation grade, and B7-H4 expression was correlated with tumor size, lymph-node metastasis, and invasion depth. High B7-H4 expression was also correlated with poor survival in pancreatic cancer. We determined the value of these three B7 family molecules in the postoperative survival prognosis for patients with pancreatic cancer, and pancreatic cancer patients with less coexpression of the B7 family of molecules had a significantly higher survival rate. B7-H1 expression was found to be negatively related to the intensity of both CD3+ T cells and CD8+ T cells, and B7-H4 expression was negatively related to CD3+ T-cell infiltration intensity, but not to CD8+ T cells. Conclusion B7-H1, B7-H3, and B7-H4 are involved in pancreatic cancer progression, and their coexpression could be a valuable prognostic indicator. Negative regulation of T-cell infiltration might be the main mechanism of action of the B7 family of molecules in pancreatic cancer.

Prognostic significance of Beclin-1 expression in colorectal cancer: a meta-analysis.

OBJECTIVE Beclin-1 has recently been observed as an essential marker of autophagy in several cancers. However, the prognostic role of Beclin-1 in colorectal neoplasia remains controversial. Our study aimed to evaluate the potential association between Beclin-1 expression and the outcome of colorectal cancer patients. MATERIALS AND METHODS All related studies were systematically searched in Pubmed, Embase, Springer and Chinese National Knowledge Infrastructure databases (CNKI), and then a meta-analysis was performed to determine the association of Beclin-1 expression with clinical outcomes. Finally, a total of 6 articles were included in our analysis. RESULTS Our data showed that high Beclin-1 expression in patients with CRC was associated with poor prognosis in terms of tumor distant metastasis (OR=2.090, 95%CI=1.061-4.119, p=0.033) and overall survival (RR=1.422, 95%CI=1.032-1.959, p=0.031). However, we did not found any correlation between Beclin-1 over-expression and tumor differentiation (OR=1.711, 95%CI=0.920-3.183, p=0.090). In addition, there was no evidence of publication bias as suggested by Eggers tests for tumor distant metastasis (p=1.000), differentiation (p=1.000) and OS (p=0.308). CONCLUSIONS Our present meta-analysis indicated that elevated Beclin-1 expression iss associated with tumor metastasis and a poor prognosis in patients with CRC. Beclin-1 might serve as an efficient prognostic indicator in CRC, and could be a new molecular target in CRC therapy.

Long noncoding RNA OR3A4 promotes metastasis and tumorigenicity in gastric cancer

The contribution of long noncoding RNAs (lncRNAs) to metastasis of gastric cancer remains largely unknown. We used microarray analysis to identify lncRNAs differentially expressed between normal gastric tissues and gastric cancer tissues and validated these differences in quantitative real-time (qRT)-PCR experiments. The expression levels of lncRNA olfactory receptor, family 3, subfamily A, member 4 (OR3A4) were significantly associated with lymphatic metastasis, the depth of cancer invasion, and distal metastasis in 130 paired gastric cancer tissues. The effects of OR3A4 were assessed by overexpressing and silencing OR3A4 in gastric cancer cells. OR3A4 promoted cancer cell growth, angiogenesis, metastasis, and tumorigenesis in vitro and in vivo. Global microarray analysis combined with RT-PCR, RNA immunoprecipitation, and RNA pull-down analyses after OR3A4 transfection demonstrated that OR3A4 influenced biologic functions in gastric cancer cells via regulating the activation of PDLIM2, MACC1, NTN4, and GNB2L1. Our results reveal OR3A4 as an oncogenic lncRNA that promotes tumor progression, Therefore, lncRNAs might function as key regulatory hubs in gastric cancer progression.

Clinical and prognostic relevance of EZH2 in breast cancer: A meta-analysis.

The polycomb group protein enhancer of zeste homolog 2 (EZH2) is regarded as a tightly linking oncogene in many types of cancer. However, the prognostic role of EZH2 in breast cancer (BC) still remains controversial. Our study aimed to evaluate the clinical and prognostic relevance of EZH2 in BC patients based on published studies. 11 studies totally containing 2330 patients (1052 EZH2-positive and 1278 EZH2-negative) were included in our meta-analysis. Our data showed that EZH2 over-expression was significantly associated with estrogen receptor (ER) negativity [OR=0.227, 95% CI=0.174-0.297, P=0.000], progesterone receptor (PR) negativity [OR=0.454, 95% CI=0.300-0.687, P=0.000], human epidermal growth factor receptor type 2 (HER-2) positivity [OR=1.846, 95% CI=1.366-2.496, P=0.000], invasive ductal cancer (IDC) [OR=2.237, 95% CI=1.489-3.361, P=0.000], race (Caucasian) [OR=0.707, 95% CI=0.522-0.957, P=0.025], high histological grade [OR=3.177, 95% CI=2.012-5.014, P=0.000] and triple-negative status (TNBCs) [OR=5.380, 95% CI=1.065-27.187, P=0.042], which led to a poor OS rate in BC [RR=2.193, 95% CI=1.495-3.217, P=0.000]. In conclusion, EZH2 participated in the progression of BC as a putative factor, and over-expression of EZH2 was distinctly correlated with a poor patient survival. EZH2 may serve as a prognostic biomarker and target in BC patients.

Long noncoding RNA C21orF96 promotes the migration, invasion and lymph node metastasis in gastric cancer

Lymphatic metastasis is a primary cause of gastric cancer-related death, yet factors governing tumor cell lymphatic metastasis have not been fully elucidated. Little is known about the contributions of long noncoding RNAs (lncRNAs) to lymphatic metastasis in gastric cancer. Differentially expressional lncRNAs between metastatic lymph node tissues and normal lymph node tissues were identified and validated by microarray and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. Our results found that the expression level of C21orF96 was over-expressed in positive lymph node tissues and gastric cancer tissues. We evaluated the altered expressions of C21orF96 in gastric cancer tissues comparing to adjacent normal specimens, and their association with clinicopathological factors. We showed that the expression levels of C21orF96 were associated with gross appearance, lymphatic metastasis and distal metastasis. The effect of C21orF96 was assessed by over-expressing the lncRNA. We also found that C21orF96 promoted the tubular formation, migration and invasion. Together, our results suggest that C21orF96 is an oncogenic lncRNA that promotes tumor progression and plays a pivotal role in the development of gastric cancer.

Silencing NPAS2 promotes cell growth and invasion in DLD-1 cells and correlated with poor prognosis of colorectal cancer

Emerging evidences show that circadian rhythm disorder is an important factor of tumor initiation and development. Neuronal PAS domain protein2 (NPAS2), which is the largest circadian gene, has been proved to be a novel prognostic biomarker in breast cancer and non-Hodgkins lymphoma. However, the potential functions of NPAS2 in colorectal cancer are still unknown. In our present study, we detected the mRNA expressions of NPAS2 in 108 CRC patients by RT-PCR, and found that NPAS2 expression was significantly down-regulated in tumor tissues than that in NATs. Clinicopathologic analysis revealed that low expression of NPAS2 was associated with the tumor size, TNM stage and tumor distance metastasis in colorectal cancer (p<0.05). Furthermore, we effectively down-regulated NPAS2 mRNA expression by transfecting RNA interfere fragments into DLD-1 cells, and our results in vitro demonstrated that silencing NPAS2 expression could promote cell proliferation, cell invasion and increase the wound healing ability (p<0.05). However, down-regulating NPAS2 expression did not influence the apoptotic rate in DLD-1 cells (p>0.05). In conclusion, our study suggested that NPAS2, functioned as a potential tumor suppressor gene, could serve as a promising target and potential prognostic indicator for colorectal cancer.

Lgr5 Contributes to Intestinal Metaplasia During Gastric Carcinogenesis: A Meta analysis.

Lgr5, which is a somatic stem cell biomarker, plays an important role during the carcinogenesis and tumor progression. But in gastric cancer, the functions of Lgr5 still remain controversial. Our meta-analysis is performed to evaluate the potential associations between Lgr5 and the outcome of patients with gastric cancer (GC). In our study, a total of 6 studies comprising 1092 patients were included. Our results demonstrated that high expression of Lgr5 was not associated to the depth of tumor invasion (pooled OR=1.395, CI95%=0.652-2.958, P=0.392, random-effect), gender of patients (pooled OR=1.264, 95%CI=0.933-1.713, P=0.13, fixed effect), tumor distance metastasis (pooled OR=1.1, 95%CI=0.734-3.754, P=0.772, random-effect), tumor size (pooled OR=0.977, 95%CI=0.705-1.353, P=0.887, random-effect), TNM stages (pooled OR=1.304, 95%CI=0.449-3.789, p=0.625, random-effect) and lymph node metastasis (pooled OR=1.507, 95%CI=0.829-2.738, P=0.178, random-effect). But interestingly, the expression of Lgr5 was associated with the age of GC patients (pooled OR=1.731, 95%CI=1.082-2.769, P=0.02) and Lauren type of GC (OR=2.284, 95%CI=1.611-3.238, P<0.001). Our findings indicated that Lgr5 might contribute to the intestinal metaplasia during gastric carcinogenesis. This difference in pathological Laurens classification is of practical significance for us to make about appropriate treatment options in gastric cancer.