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.
The 66 kDa estrogen receptor alpha (ERα66) is the main molecular target for endocrine therapy such as tamoxifen treatment. However, many patients develop resistance with unclear mechanisms. In a large cohort study of breast cancer patients who underwent surgery followed by tamoxifen treatment, we demonstrate that ERα36, a variant of ERα66, correlates with poor prognosis. Mechanistically, tamoxifen directly binds and activates ERα36 to enhance the stemness and metastasis of breast cancer cells via transcriptional stimulation of aldehyde dehydrogenase 1A1 (ALDH1A1). Consistently, the tamoxifen-induced stemness and metastasis can be attenuated by either ALDH1 inhibitors or a specific ERα36 antibody. Thus, tamoxifen acts as an agonist on ERα36 in breast cancer cells, which accounts for hormone therapy resistance and metastasis of breast cancer. Our study not only reveals ERα36 as a stratifying marker for endocrine therapy but also provides a promising therapeutic avenue for tamoxifen-resistant breast cancer.
Long intergenic non-coding RNA 152 (LINC00152) is a recently identified tumor-promoting long non-coding RNA. However, the biological functions of LINC00152 in colorectal cancer (CRC) remain unclear and require further research. The aim of the present study is to explore the roles of LINC00152 in cellular function and its possible molecular mechanism. In this study, we discovered that LINC00152 was overexpressed in CRC tissues and negatively related to the survival time of CRC patients. Functional analyses revealed that LINC00152 could promote cell proliferation. Furthermore, LINC00152 could increase the resistance of CRC cells to 5-fluorouracil (5-FU) by suppressing apoptosis. We also discovered that LINC00152 could enhance cell migration and invasion. Mechanistic studies demonstrated that LINC00152 could regulate the expression of NOTCH1 through sponging miR-139-5p and inhibiting its activity from promoting CRC progression and development. Altogether, our work points out a novel LINC00152/miR-139-5p/NOTCH1 regulatory axis in CRC progression and development.
a b s t r a c tTo investigate the role of microRNAs in the development of chemoresistance and related epithelialmesenchymal transition (EMT), we examined the effect of miR-489 in adriamycin (ADM)-resistant human breast cancer cells (MCF-7/ADM). MiR-489 was significantly suppressed in MCF-7/ADM cells compared with chemosensitive parental control MCF-7/WT cells. Forced-expression of miR-489 reversed chemoresistance. Furthermore, Smad3 was identified as the target of miR-489 and is highly expressed in MCF-7/ADM cells. Forced expression of miR-489 both inhibited Smad3 expression and Smad3 related EMT properties. Finally, the interactions between Smad3, miR-489 and EMT were confirmed in chemoresistant tumor xenografts and clinical samples, indicating their potential implication for treatment of chemoresistance.
Emerging research has indicated that circular RNAs (circRNAs), a novel class of noncoding RNAs, play a vital role in human tumorigenesis and progression. Our previous results suggested that hsa_circ_0006528 (circ_0006528), a circRNA with an unknown function, mediates adriamycin resistance in human breast cancer cells. However, the role of circ_0006528 in breast cancer progression remains unknown. Here, we investigated the probable involvement of circ_0006528 in breast cancer. We analyzed a cohort of 97 patients and found that circ_0006528 expression was significantly upregulated in human breast cancer tissues compared with that in adjacent nontumorous tissues and was significantly associated with advanced tumor-nodemetastasis (TNM) stage and poor prognosis. In addition, we found that in breast cancer cells, circ_0006528 could promote DNA synthesis and cell proliferation, invasion, and migration. Downregulating circ_0006528 induced G2 phase arrest and cell apoptosis. Further mechanistic studies revealed that circ_0006528 could sponge endogenous miR-7-5p and inhibit its activity. We also identified Raf1, which activates the MAPK/ERK signaling pathway, as a target of miR-7-5p and determined that circ_0006528 promotes breast cancer growth, invasion, and migration by promoting the expression of Raf1 and activates the MAPK/ERK pathway. Thus, this study provides the first evidence of the circ_0006528/miR-7-5p/Raf1/MEK/ERK regulatory network in the development of breast cancer and suggests that circ_0006528 is a potential therapeutic target and prognostic predictor for breast cancer.breast cancer, hsa_circ_0006528, invasion, migration, miR-7-5p, proliferation | INTRODUCTIONBreast cancer is the most prevalent cancer in women worldwide and represents a serious public health problem. One complication in the clinical management of breast cancer is the tendency of malignant cells to shed into the circulation during the early stages of tumor development, 1,2 causing the formation of metastatic foci, a phenomenon that directly contributes to approximately 90% of breast cancerrelated mortality. 3,4 The precise genetic and epigenetic mechanisms that regulate the formation and malignant progression of tumors remain unclear and require further study. Therefore, it is essential to Danfeng Gao, Xiaowei Qi, and Xiufen Zhang contributed equally to this work. |
Background: Resistance to 5-fluorouracil leads to the failure of chemotherapy for colorectal cancer. Results: Suppressing TrpC5 expression decreased nuclear -catenin accumulation, reduced the induction of ABCB1, and reversed 5-fluorouracil resistance. Conclusion: TrpC5 is essential in ABCB1 induction and drug resistance in human colorectal cancer cells. Significance: These findings may help develop a novel target for overcoming resistance to chemotherapy in colorectal cancer.
Though proposed as a promising target antigen for cancer immunotherapy, the prognostic value of Wilms' tumor 1 (WT1) in solid tumors remains inconclusive. Here, we report a systematic review and meta-analysis of the association between WT1 expression and prognosis in solid tumors. PubMed, Web of Science and Google Scholar were searched to identify studies exploring the impact of WT1 on clinical outcomes, including overall survival (OS), disease-specific survival (DSS), disease-free survival (DFS), relapse/recurrence-free survival (RFS) or progression-free survival (PFS), in solid cancer patients. Hazard ratio (HR) and 95% confidence interval (CI) were applied to assess the strength of these associations. Finally, a total of 29 eligible studies with 4090 patients were identified for qualitative analysis, and 22 studies with 3620 patients were enrolled for quantitative synthesis. Overall, positive expression of WT1 was significantly associated with worse OS (metaHR = 1.48, 95% CI = 1.11–1.97) and DFS/RFS/PFS (metaHR = 2.14, 95% CI = 1.42–3.21). Subgroup analyses showed that WT1 positive expression could independently predict unfavorable DFS/RFS/PFS (metaHR = 1.86, 95%CI = 1.04–3.35). In summary, our study suggests that WT1 may be a potential marker to predict DFS/RFS/PFS in solid tumor patients. Further studies are needed to confirm the role of WT1 expression in clinical practice.
Diagnosis of bladder cancer, one of the most common types of human cancer, at an early (nonmuscle-invasive) stage is the best way to reduce the mortality rate. Tumor malignancy in general is closely associated with alterations of glycan expression. Glycosylation status, particularly global glycomes, in bladder cancer has not been well studied. We integrated lectin microarray and mass spectrometry (MS) methods to quantitatively analyze and compare glycan expression in four bladder cancer cell lines (KK47, YTS1, J82, T24) and one normal bladder mucosa cell line (HCV29). Glycopattern alterations were analyzed using lectin microarray analysis and confirmed by lectin staining and lectin blotting. Associations of glycopatterns with diverging stages were evaluated by lectin histochemistry on tissue microarrays. N-Glycans were derivatized by amidation of sialylated glycans with acetohydrazide and reductive amination with the stable isotope tags [(12)C6]- and [(13)C6]-aniline, and were quantitatively analyzed by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF/TOF-MS). N-Glycan biosynthesis-associated proteins were quantitatively analyzed by a stable isotope labeling by amino acids in cell culture (SILAC) proteomics method, which revealed significant differences in expression of 13 glycosyltransferases and 4 glycosidases. Our findings indicate that sialyl Lewis X (sLe(x)), terminal GalNAc and Gal, and high mannose-type N-glycans were more highly expressed in bladder cancer cells and tissues than in normal cells. Bladder cancer cells showed high expression of core-fucosylated N-glycans but low expression of terminally fucosylated N-glycans. Each of these glycome changes may be directly related to bladder cancer progression.
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