Exosomal MALAT1 sponges miR-26a/26b to promote the invasion and metastasis of colorectal cancer via FUT4 enhanced fucosylation and PI3K/Akt pathway.

BACKGROUND: Exosomes are vesicles of endocytic origin released by various cell types and emerging as important mediators in tumor cells. Human metastases-associated lung adenocarcinoma transcript 1 (MALAT1) is a long non-coding RNA known to promote cell proliferation, metastasis, and invasion in colorectal cancer (CRC). METHODS: The expression of MALAT1 was analyzed in CRC using qRT-PCR. FUT4 and fucosylation levels were detected in CRC clinical samples and CRC cell lines by immunofluorescent staining, western blot and lectin blot analysis. CRC derived exosomes were isolated and used to examine their tumor-promoting effects in vitro and in vivo. RESULTS: The invasive and metastatic abilities of primary CRC cells were enhanced after exposure to exosomes derived from highly metastatic CRC cells, which increased the fucosyltransferase 4 (FUT4) levels and fucosylation not by directly transmitting FUT4 mRNA. Exosomal MALAT1 increased FUT4 expresssion via sponging miR-26a/26b. Furthermore, MALAT1/miR-26a/26b/FUT4 axis played an important role in exosome-mediated CRC progression. Exosomal MALAT1 also mediated FUT4-associated fucosylation and activated the PI3K/AKT/mTOR pathway. CONCLUSIONS: These data indicated that exosomal MALAT1 promoted the malignant behavior of CRC cells by sponging miR-26a/26b via regulating FUT4 and activating PI3K/Akt/mTOR pathway.

Retraction Note: Aberrant mannosylation profile and FTX/miR-342/ALG3-axis contribute to development of drug resistance in acute myeloid leukemia.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The HOTAIR/miR-214/ST6GAL1 crosstalk modulates colorectal cancer procession through mediating sialylated c-Met via JAK2/STAT3 cascade.

BACKGROUND: The regulatory non-coding RNAs, including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), emerge as pivotal markers during tumor progression. Abnormal sialylated glycoprotein often leads to the malignancy of colorectal cancer (CRC). METHODS: Differential levels of HOTAIR and ST6GAL1 are analyzed by qRT-PCR. Functionally, CRC cell proliferation, aggressiveness and apoptosis are measured through relevant experiments, including CCK8 assay, colony formation assay, transwell assay, western blot and flow cytometry. Dual-luciferase reporter gene assay and RIP assay confirm the direct interaction between HOTAIR and miR-214. The lung metastasis, liver metatstasis and xenografts nude mice models are established to show the in vivo effect of HOATIR. RESULTS: Here, differential levels of HOTAIR and ST6GAL1 are primarily observed in CRC samples and cells. Upregulated HOTAIR and ST6GAL1 are crucial predictors for poor CRC prognosis. Altered level of ST6GAL1 modulates CRC malignancy. Furthermore, ST6GAL1 and HOTAIR are confirmed as the direct targets of miR-214, and ST6GAL1 is regulated by HOTAIR via sponging miR-214. ST6GAL1 induces the elevated metabolic sialylation of c-Met, which is co-mediated by HOTAIR and miR-214. Sialylated c-Met affects the activity of JAK2/STAT3 pathway. The regulatory role of HOTAIR/miR-214/ST6GAL1 axis also impacts CRC procession. In addition, HOTAIR mediates lung metastasis, liver metastasis and tumorigenesis in vivo. ShHOTAIR and AMG-208 are combined to inhibit tumorigenesis for successful drug development. CONCLUSION: The HOTAIR/miR-214/ST6GAL1 axis commands the CRC malignancy by modifying c-Met with sialylation and activating JAK2/STAT3 pathway. Our study presents novel insights into CRC progression and provided prospective therapeutic target for CRC.

Correction to: LINC01296/miR-26a/GALNT3 axis contributes to colorectal cancer progression by regulating O-glycosylated MUC1 via PI3K/AKT pathway.

In the publication of this article [1], there is an error in Fig. 5C (panel 4, group of InmiR-26a + silinc01296 in SW620). The revised Fig. 5 which includes 5C has now been included in this correction.

Correction to: The regulatory ZFAS1/miR-150/ST6GAL1 crosstalk modulates sialylation of EGFR via PI3K/Akt pathway in T-cell acute lymphoblastic leukemia.

In the original publication of this article [1], there is a mistake in Fig. 4E.

The regulatory ZFAS1/miR-150/ST6GAL1 crosstalk modulates sialylation of EGFR via PI3K/Akt pathway in T-cell acute lymphoblastic leukemia.

BACKGROUND: Noncoding RNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are becoming key parts in the development of multidrug resistance (MDR) in T-cell acute lymphoblastic leukemia (T-ALL). Abnormal expression in sialyated N-glycans have been observed in MDR leukemia. However, the role of sialylation regulated MDR remains poorly understood. The aim of this work is to analyze the alternation of N-glycans in T-ALL MDR. METHODS: Here, mass spectrometry (MS) is analyzed to screen the N-glycan profiles from ALL cell line CR and adriamycin (ADR)-resistant CR (CR/A) cells. The expression of sialyltransferase (ST) genes in T-ALL cell lines and bone marrow mononuclear cells (BMMCs) of T-ALL patients were analyzed using qRT-PCR. Functionally, T-ALL cell proliferation and MDR are detected through CCK8 assay, colony formation assay, western blot and flow cytometry. RIP assay and Dual-luciferase reporter gene assay confirm the binding association between ZFAS1 and miR-150. Xenograft nude mice models are used to determine the role of ST6GAL1 in vivo. RESULTS: Elevated expression of α2, 6-sialyltransferase 1 (ST6GAL1) has been detected. The altered level of ST6GAL1 was corresponding to the drug-resistant phenotype of T-ALL cell lines both in vitro and in vivo. ZFAS1/miR-150/ST6GAL1 axis was existed in T-ALL cell lines. MiR-150 was downregulated and inversely correlated to ST6GAL1 expression. ZFAS1 was a direct target of miR-150 and positively modulated ST6GAL1 level by binding miR-150. ZFAS1/miR-150/ST6GAL1 axis functioned to regulate ADR-resistant cell growth and apoptosis. Besides, EGFR was demonstrated to be a substrate of ST6GAL1, and the sialylated EGFR had an impact on the PI3K/Akt pathway. CONCLUSION: Results suggested that ZFAS1/miR-150/ST6GAL1 axis involves in the progression of T-ALL/MDR further mediates sialylated EGFR via PI3K/Akt pathway. This work might have an application against T-ALL MDR.

MiR-29b/Sp1/FUT4 axis modulates the malignancy of leukemia stem cells by regulating fucosylation via Wnt/ß-catenin pathway in acute myeloid leukemia.

BACKGROUND: Acute myeloid leukemia (AML) is initiated and maintained by a unique, small subset of leukemia stem cells (LSCs). LSCs are characterized by unrestricted self-renewal and contribute to the malignancy of leukemia. Aberrant protein fucosylation is associated with AML progression. However, it is still less understood that the miR-29b/Sp1/FUT4 crosstalk involved in the fucosylation-mediated LSCs malignancy in AML. METHODS: AML cell lines were sorted by magnetic microbeads to obtain the CD34 + CD38- sub-population. The key biomarkers for LSCs were identified by flow cytometry. Fucosyltransferase genes were screened by qRT-PCR, and FUT4 was focused. Effect of FUT4 on LSCs malignancy was determined by CCK8 assay, sphere formation assay, immunofluorescence staining, apoptosis and in vivo xenografts experiments. The linkage of FUT4 promoter and Sp1 was confirmed by dual-luciferase reporter gene assay. ChIP-PCR assay was used to show the directly binding of Sp1 and FUT4 promoter. Activity of Wnt//ß-catenin pathway was determined by western blot. Overall survival curves were diagrammed by Kaplan-Meier analysis. RESULTS: Here, the expressional profiles of 11 fucosyltransferase genes were different comparing LSCs and non-LSCs of KG-1a and MOLM13 cells, whereas CD34 + CD38- cells exhibited higher expression of FUT4. Functionally, alteration of FUT4 in CD34 + CD38- cells modulated LSCs malignant behaviors both in vitro and in vivo. Transcriptional inhibitor actinomycin D (Act D) or translational inhibitor cycloheximide (CHX) prevented LSCs progression, and Sp1 was identified as the efficient regulator of FUT4 transcription. Moreover, miR-29b directly affected the binding of Sp1 and FUT4 promoter region, which further mediated LSCs proliferation, apoptosis and drug-resistance through fucosylated-CD44 via activation of Wnt/ß-catenin pathway. Clinically, Sp1 and FUT4 were up-regulated and positively correlated with poor overall survival of AML patients. CONCLUSION: These data indicated that miR-29b/Sp1/FUT4 axis promoted the malignant behaviors of LSCs by regulating fucosylated CD44 via Wnt/ß-catenin pathway. Identifying LSCs surface markers and targeting LSCs were important for the development of potential therapies in AML.

Correction to: LINC01296/miR-26a/GALNT3 axis contributes to colorectal cancer progression by regulating O-glycosylated MUC1 via PI3K/AKT pathway.

In the publication of this article [1], there is an error in Fig. 5G (panel 2, group of InmiR-26a + siSCR in HCT-8/5-FU, treated with 284.3 µM).

HOTAIR/miR-326/FUT6 axis facilitates colorectal cancer progression through regulating fucosylation of CD44 via PI3K/AKT/mTOR pathway.

Metastasis is the main cause of death in colorectal cancer (CRC) patients. Aberrant fucosylation, catalyzed by the specific fucosyltransferases (FUTs), is associated with malignant behaviors. Non-conding RNAs, including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), emerge as key molecules in cancer malignancy. The aim of this study was to investigate HOTAIR/miR-326/FUT6 axis modified fucosylation on sLeX-CD44 (HCELL), which served as E-selectin ligand during CRC progression. Higher levels of HOTAIR and FUT6 were verified in CRC tissues and cell lines, with a positive correlation. HOTAIR was associated with poor clinical prognosis of CRC. Altered HOTAIR levels influenced proliferation, aggressiveness, apoptosis and tumorigenesis of CRC cells. HOTAIR directly harbored miR-326 binding sites and regulated FUT6 expression. Further results corroborated that HOTAIR/miR-326/FUT6 axis modified α1, 3-fucosylation of CD44, which mediated CRC malignancy. Co-modulation of HOTAIR, miR-326 and FUT6 impacted α1, 3-fucosylated CD44, which further triggered PI3K/AKT/mTOR pathway. HOTAIR also mediated CRC tumorigenesis and liver metastasis in vivo. Thus, our findings indicated that HOTAIR/miR-326/FUT6 axis mediated CRC procession through α1, 3-fucosylated CD44 via PI3K/AKT/mTOR pathway. This work rendered new therapeutic targets for CRC.

The potential of exosomes derived from colorectal cancer as a biomarker.

Colorectal cancer (CRC) is one of the most frequent causes of cancer death. The diagnosis and treatment for metastatic CRC and patients with drug resistance remains poor. Cancer cells characteristically produce and release exosomes, which act as a new signal pattern in the occurrence and development of tumors. Circulating exosomes constitute promising biomarkers for early diagnosis of cancer patients. However, the potential of exosomes for clinical biomarker is hampered by their variousness and multi-sources. To this aim, we set out to solve the problem of discrimination and classification of exosomes. The cell culture supernatants of CRC cells, renal cell carcinoma cells and breast cancer cells were used for isolating exosomes. Then characteristic exosomal tumor markers were explored by Roche Cobas E601 fully automated electrochemiluminescence immunoassay systems, western blot and flow cytometry analysis. The results showed that CK19 was commonly expressed in exosomes derived from colorectal cells, TAG72 was mainly expressed in exosomes of 5-FU-resistant CRC cells and CA125 in those of high metastatic CRC cells. In addition, tumor interstitial fluid derived exosomes and patients' plasma derived exosomes showed different levels of CK19, TAG72 and CA125. Collectively, these data indicated that exosomes derived CK19 is correlated with colorectal tissue. TAG72-rich exosomes indicate that CRC patients might be resistant to 5-Fluorouraci. CA125-rich exosomes might be as metastatic CRC markers. These provide a good prospect for cell exosomes as novel, non-invasive clinical tool for diagnosing CRC and predicting its progression.

LINC01296/miR-26a/GALNT3 axis contributes to colorectal cancer progression by regulating O-glycosylated MUC1 via PI3K/AKT pathway.

BACKGROUND: Long non-coding RNAs (LncRNAs) emerging as pivotal marker in the procession of cancer, including colorectal cancer (CRC). Abnormal O-glycosylation is a crucial modification during cancer malignancy. The aim of this work is to analyze the alteration of O-glycosylation involved in CRC progression. METHODS: qRT-PCR is utilized to screen the differential linc01296 expression in CRC tissues and cell lines. Functionally, CRC cell proliferation, aggressiveness and apoptosis are measured through relevant experiments, including CCK8 assay, colony formation assay, transwell assay, western blot and flow cytometry. Dual-luciferase reporter gene assay and RIP assay confirm the direct interaction between linc01296 and miR-26a. The xenografts and liver metatstatic nude mice models are established to show the inner effect of linc01296. RESULTS: Differential expression of linc01296 is confirmed and closely correlated with the malignancy of CRC cell lines and poor clinical prognosis. Moreover, alteration of linc01296 affects CRC cell proliferation, metastasis and chemoresistance to 5-fluorouracil (5-FU) in vitro. Mechanically, linc01296 acts as a direct target of miR-26a, and thereby influenced CRC malignancy. Our investigation corroborates that linc01296 functions as an endogenous sponge of miR-26a to regulate mucin1 (MUC1) expression, catalyzed by GALNT3, which modulates the activity of PI3K/AKT pathway. Interestingly, upregulated linc01296 promotes the tumorigensis, liver metastasis and chemoresistance of CRC cell lines in vivo. CONCLUSION: These new findings indicate that linc01296/miR-26a/GALNT3 axis involves in the progression of CRC cells, illuminating the possible mechanism mediated by O-glycosylated MUC1 via PI3K/AKT pathway. This work renders potential diagnostic biomarkers and prospective therapeutic targets for CRC.

Aberrant mannosylation profile and FTX/miR-342/ALG3-axis contribute to development of drug resistance in acute myeloid leukemia.

Drug-resistance is a major problem in acute myeloid leukemia (AML) chemotherapy. Aberrant changes in specific N-glycans have been observed in leukemia multidrug resistance (MDR). MicroRNAs (miRNAs) and long non coding RNAs (lncRNAs) act as key players in the development of AML resistance to chemotherapy. In the present study, the N-glycan profiles of membrane proteins were analyzed from adriamycin (ADR)-resistant U937/ADR cells and sensitive line U937 cells using mass spectrometry (MS). The composition profiling of high-mannose N-glycans differed in U937/ADR and U937 cell lines. Lectin microarray showed that the strong binding of membrane proteins was observed for MAN-M and ConA lectins, which were specific for mannose. These binding were also validated by flow cytometry. Importantly, the alteration of high-mannose N-glycan was further confirmed by detecting the enzyme level of ALG family. The altered level of ALG3 was found corresponding to the drug-resistant phenotype of AML cell lines both in vitro and in vivo. Mechanistically, miR-342 was found to be dysregulated and inversely correlated to ALG3 expression, targeting its 3'-UTR. LncRNA FTX was a direct target of miR-342 and positively modulated ALG3 expression by competitively binding miR-342 in AML cell lines. Functionally, we found that FTX directly interacted with miR-342 to regulate ALG3 expression and function, including ADR-resistant cell growth and apoptosis. The observation suggested that high-mannose N-glycans and mannosyltransferase ALG3 affected drug-resistance in AML cells. FTX/miR-342/ALG3 axis could potentially be used for the targets to overcome therapeutic resistance in AML.