Yong Mao

LncRNA—UCA1 enhances cell proliferation and 5-fluorouracil resistance in colorectal cancer by inhibiting miR-204-5p

Recent preliminary studies reported the in vitro tumor-promoting effects of long non-coding RNA urothelial carcinoma associated 1 (UCA1) in colorectal cancer (CRC). However, the in vivo functions and molecular mechanism of UCA1 in CRC remain unclear. Therefore, we investigated the detailed role and mechanism of UCA1 in CRC. We found that UCA1 was up-regulated in CRCs and negatively correlated with survival time in two CRC cohorts. Functional assays revealed the in vitro and in vivo growth-promoting function of UCA1 and revealed that UCA1 can decrease the sensitivity of CRC cells to 5-FU by attenuating apoptosis. Further mechanistic studies revealed that UCA1 could sponge endogenous miR-204-5p and inhibit its activity. We also identified CREB1 as a new target of miR-204-5p. The protein levels of CREB1 were significantly up-regulated in CRCs, negatively associated with survival time and positively correlated with the UCA1 expression. The present work provides the first evidence of a UCA1-miR-204-5p-CREB1/BCL2/RAB22A regulatory network in CRC and reveals that UCA1 and CREB1 are potential new oncogenes and prognostic factors for CRC.

Acquisition of paclitaxel resistance via PI3K‑dependent epithelial‑mesenchymal transition in A2780 human ovarian cancer cells.

Epithelial ovarian cancer is a major cause of mortality among women with gynecological malignancies. Paclitaxel is commonly used for chemotherapy of ovarian cancer, yet its efficacy is limited by chemoresistance. Generally, drug resistance is associated with acquisition of the epithelial-mesenchymal transition (EMT) in cancer. The aim of the present study was to determine whether the EMT is involved in acquired resistance to paclitaxel in A2780 human ovarian cancer cells. Using the paclitaxel-resistant A2780/PTX cell line, we examined the cellular morphology, molecular changes, migration and proliferation consistent with the EMT. Furthermore, we found that inhibition of phosphatidylinositol 3-kinase (PI3K) activity reduced the proliferation and migration and restored their sensitivity to paclitaxel. Our study provides new insights into EMT-like phenotypic changes that are linked to paclitaxel resistance in A2780 cells. We believe that inhibition of the PI3K signaling pathway could provide a novel therapeutic approach to overcome chemoresistance and prevent metastasis during paclitaxel chemotherapy.

A2780 human ovarian cancer cells with acquired paclitaxel resistance display cancer stem cell properties

The use of chemotherapy to treat cancer is effective, but chemoresistance reduces this efficacy. Chemotherapy resistance involves several mechanisms, including the cancer stem cell (CSC) concept. The aim of the present study was to assess whether paclitaxel-resistant epithelial ovarian carcinoma is capable of generating cells with CSC-like properties. Using the paclitaxel-resistant A2780/PTX cell line, it was demonstrated that high aldehyde dehydrogenase 1 (ALDH1) activity identifies CSCs from diverse sources. Furthermore, the A2780/PTX cells had a strong ability to form colonies in soft agar assays. Notably, it was demonstrated that the inhibition of the PI3K signaling pathway abolished colony formation. These data suggest that there is a link between paclitaxel resistance and CSC enrichment. It is possible that therapeutic benefits, such as the restoration of chemosensitivity or the suppression of tumorigenicity, may be enabled by gaining further insights into the mechanisms underlying chemoresistance and the generation of CSCs.

A polymorphism in ABCC4 is related to efficacy of 5-FU/capecitabine-based chemotherapy in colorectal cancer patients

To investigate the association of microRNA (miRNA) binding-site polymorphisms in the drug transporter genes with the efficacy of 5-Fluorouracil (5-FU)/capecitabine-based chemotherapy in colorectal cancer (CRC), 6 polymorphisms were determined in 432 CRC patients by using DNA sequencing method. The impacts of the polymorphisms on the miRNA-mediated regulation of gene expression were evaluated by using the methods including quantitative real-time PCR, western blotting, and luciferase reporter assays. The effects of miRNA on the intracellular concentration and cytotoxicity of 5-FU in CRC cells were measured by high performance liquid chromatography conjected tandem mass spectrometry (HPLC-MS/MS) and MTT methods, respectively. Statistical analysis showed that a polymorphism rs3742106 in the 3′-UTR of ATP-binding cassette subfamily C member 4 (ABCC4) gene was significantly associated with the efficacy of 5-FU/capecitabine-based chemotherapy in CRC. The patients with T/T genotype had significantly higher response rate than those with G/G and G/T genotypes. The expression of ABCC4 was inhibited by miR-3190-5p through binding to the 3′-UTR of the ABCC4 gene. This regulatory role of miR-3190-5p was disrupted by rs3742106. Furthermore, we found that the intracellular concentration of 5-FU was elevated by miR-3190-5p, and consequently the sensitivity of CRC cells to 5-FU was also enhanced. Rs3742106 might be regarded as a genetic biomarker for individualized use of 5-FU and capecitabine in CRC.

Cancer cell‑expressed B7‑H3 regulates the differentiation of tumor‑associated macrophages in human colorectal carcinoma

Co-stimulatory molecule B7 homolog 3 protein (B7-H3) has been described as an important tumor antigen in various human tumors. The exact role of B7-H3 in tumor progression and its receptor are still ambiguous. The phenotype and the function of tumor-associated macrophages (TAMs) in human solid tumors are complicated and could contribute to the shaping of the tumor microenvironment. In the present study, B7-H3 expression and lymphocyte infiltration were investigated by immunohistochemistry in 117 colorectal carcinoma (CRC) patients. B7-H3 expression was positively associated with the infiltrating density of macrophage in CRC tissues, and B7-H3 expression and the infiltrating density of macrophages were negatively associated with the overall survival rate of patients. The putative B7-H3 receptor was found on activated monocytes and macrophages, indicating the direct function of B7-H3 signal on macrophages. Additional results revealed that during the differentiation of TAMs, B7-H3 promoted the polarization of type 2 macrophages (M2s) and switch of the M1 phenotype to the M2 phenotype. Thus, B7-H3 signaling promotes M2 differentiation via the putative receptor on monocytes and macrophages. Targeting the manipulation of TAMs through the B7-H3 pathway may be valuable for the development of novel immunotherapeutic strategies against human CRC.

Clinical correlation of B7-H3 and B3GALT4 with the prognosis of colorectal cancer.

AIM To investigate the expression and clinical significance of B7 homolog 3 (B7-H3) and β-1,3-galactosyltransferase-4 (B3GALT4) in colorectal cancer (CRC) patients. METHODS Using tissue microarray, we identified the expression of B7-H3 and B3GALT4 in 223 CRC patient samples by immunohistochemistry and evaluated the possible correlation between B7-H3 and B3GALT4 and clinical outcomes. Further, the mRNA and protein expression were identified to establish the regulatory relationship of B7-H3 with B3GALT4 in vitro. RESULTS A significant positive correlation between B7-H3 and B3GALT4 was observed in CRC specimens (r = 0.219, P = 0.001). High expression of B7-H3 was identified as a significant independent predictor of poor overall survival (OS) [hazard ratio (HR) = 1.781; 95%CI: 1.027-3.089; P = 0.040]. Moreover, high expression of B3GALT4 was also recognized as an independent predictor of inferior OS (HR = 1.597; 95%CI: 1.007-2.533; P = 0.047). Additionally, CRC patients expressing both high B7-H3 and high B3GALT4 contributed to a significant decrease in OS (HR = 2.283; 95%CI: 1.289-4.042; P = 0.005). In CRC cell lines with stable expression of high B7-H3, the mRNA and protein expressions of B3GALT4 were significantly upregulated. Similarly, the expression of B3GALT4 was significantly reduced when expression of B7-H3 was knocked down. CONCLUSION The expression of B3GALT4 in CRC is positively correlated with B7-H3 expression in vitro. B7-H3/B3GLAT4 may be used as dual prognostic biomarkers for CRC.

Expression and clinical significance of negative costimulatory molecules B7-H1, B7-H3 and B7-H4 in the process of colorectal cancer’s evolution

Background: We made investigations on the expression of negative costimulatory molecules B7-H1, B7-H3, B7-H4 in lesions at various stages of human colorectal cancer (CRC) evolution. We also analyzed the relevance between its expression in CRC and pathological factors in clinic and patient survival time. We finally made a result that we can ensure the clinical significance of B7-H3, B7-H4 expression and the relationship between the B7 family molecules expression. Methods: All stages of CRC were collected, including polyps, adenomas, high-grade neoplasms, and colorectal carcinomas. There were 98 cases of resected CRC tissue, 30 cases of polyps, 30 cases of adenomas, and 25 cases of high-grade neoplasia. Then analysis the expression of three negative costimulatory molecules in all stages of colorectal tissue expression patterns, flow cytometry CD3+ T lymphocytes B7 family molecules to explore the potential value of their expression. Results: The expression of B7 family molecules in 30 cases of polyps, 30 cases of adenomas, 25 cases of high-grade neoplasia, and 98 cases of CRC tissues revealed that the B7-H1 and B7-H3 expression quantity was found in polyps, adenomas, high-grade neoplasms, as well as they were highly expressed in cancerous tissues. B7-H4 was only expressed in cancerous tissues. In the TNM stage of tumor progression, three negative costimulatory molecules were mainly expressed in the cytoplasm of tumor cells. In CRC in lymphocytes B7-H4 expression was related to patient age, mucinous adenocarcinoma, and lymph node metastasis. Survival analysis showed in CRC it was statistically significant that that the expression of B7-H3 and the survival rate of patients. We found that 92.9% of CRC patients expressed B7 family negative costimulatory molecules in varying degrees, and the prognosis and co-expression of B7 family negative co-stimulatory molecules were negatively correlated. Conclusions: Costimulatory molecules B7-H1, B7-H3 were expressed on the early stage of CRC development. The amount of CD3+ T lymphocyte infiltration in CRC was positively correlated with the survival of patients. They are the earliest molecules to participate in the progress of CRC developing in B7 family negative molecules. This suggests that B7-H1 and B7-H3 are involved in rectal carcinoma at the junction, as well as it is essential throughout the entire evolutionary process. However, it is in CRC tissues that B7-H4 only get expressed, and different expression patterns may have different clinical significances.

Polymorphisms in the ICOS/CD28-ICOSL pathway are related to capecitabine-based chemotherapy response in advanced colon cancer patients

&NA; Polymorphisms within a genes 3′‐UTR may modulate posttranscriptional regulation of gene expression, and may explain individual sensitivity of chemotherapy. To investigate the correlation between single nucleotide polymorphisms (SNPs) in 3′‐UTRs of B7/CD28 family genes and the response of capecitabine‐based chemotherapy in colon cancer, 16 SNPs were identified in 274 advanced colon cancer patients. Statistical analysis indicated that ICOS rs1559931, rs4404254, and rs4675379 were in complete linkage disequilibrium and significantly associated with chemotherapy response. Heterozygous patients with rs1559931 G/A (31.34% vs 48.29%; P = 0.016), rs4404254 T/C (30.43% vs 48.77%; P = 0.011), or rs4675379 G/C (28.13% vs 49.04%; P = 0.004) genotypes showed poorer response to chemotherapy compared to wildtype patients. Moreover, three SNPs, including ICOSL rs15927, ICOSL rs3804033 and CD28 rs3181113, were significantly associated with the occurrence of side effects of chemotherapy. In addition, patients with ICOSL rs15927 G/G (78.26%), ICOSL rs3804033 G/G (76.00%), or CD28 rs3181113 T/T (82.05%) were more prone to enduring adverse events compared to patients bearing other polymorphisms. Taken together, our findings demonstrated that polymorphisms in the 3′‐UTRs of genes in the ICOS/CD28‐ICOSL pathway may influence the efficacy and occurrence of adverse events of capecitabine‐based chemotherapy in advanced colon cancer patients. HighlightsICOS rs1559931, rs4404254, and rs4675379 correlated with chemotherapy response.ICOSL rs15927 and rs3804033 correlated with adverse events of chemotherapy.CD28 rs3181113 correlated with adverse events of chemotherapy.

Long non-coding RNA expression profiles reveals AK098783 is a biomarker to predict poor prognosis in patients with colorectal cancer

Background Long non-coding RNAs (lncRNAs) have essential regulatory function, yet their roles in colorectal cancer (CRC) are not well understood. Materials and methods Microarray was applied to detect lncRNAs expression profiles in tumor tissues, liver metastasis and paired adjacent normal tissues of CRC. And using RT-PCR to verify chip results. Results A total of 10 680 lncRNAs demonstrated differential expressions (fold change ≥2) between tumor tissues and adjacent normal tissues; furthermore there were 2970 lncRNAs, which showed different expression level between CRC tissues with liver metastasis and adjacent normal tissues. Especially, lncRNA-AK098783 expression level was frequently higher in cancerous tissues than corresponding noncancerous tissue. Higher AK098783 expression was significantly correlated with shortened overall survival (P < 0.001) and distant metastasis (P < 0.001). Conclusions Our results suggest that AK098783 is involved in distant metastasis and dramatically associated with poor prognosis in patients with CRC.

ACOT1 expression is associated with poor prognosis in gastric adenocarcinoma

Acyl-CoA thioesterase 1 (ACOT1) is an important isoform of the ACOT family that catalyzes the reaction of fatty acyl-CoAs to CoA-SH and free fatty acids. Recent studies of gastrointestinal tumor metabolism suggest that there is abnormal metabolism of lipids and fatty acids during tumor progression. However, the function and contribution of ACOT1 in gastric cancer development are still poorly understood. In addition, GLI3 is a major transcription factor in the regulation of hedgehog signaling. GLI3 mutations induce glandular expansion and intestinal metaplasia in gastric cancer, which indicates a role for GLI3 in the preneoplastic process. Thus, we investigated the relationship between ACOT1 expression and GLI3 in gastric adenocarcinoma. A tissue microarray was constructed from 280 cases of gastric adenocarcinoma. The immunohistochemistry method was performed on tissue sections of 4 μm from each tissue microarray block. We found a significant correlation between ACOT1 expression and poor histologic grade, a lower T category, TNM stage, and increased GLI3 expression. In addition, the survival analysis revealed that the ACOT1-positive group had significantly decreased overall survival rates compared with the ACOT1-negative group. Furthermore, GLI3 expression had a significant positive correlation with ACOT1 expression in gastric adenocarcinoma cells. In summary, these findings demonstrate that increased expression of ACOT1 is correlated with pivotal clinicopathological parameters and poor prognosis in gastric adenocarcinoma through increased expression of the potential tumor-promoting protein GLI3.