Tumor suppressor LHX6 upregulation contributes to the inhibitory effect of miR-346 knockdown on colorectal cancer cell growth

ERN1 knockdown modifies the hypoxic regulation of homeobox gene expression in U87MG glioblastoma cells

OBJECTIVE.

Homeobox genes play an important role in health and disease including oncogenesis. The present investigation aimed to study ERN1-dependent hypoxic regulation of the expression of genes encoding homeobox proteins MEIS (zinc finger E-box binding homeobox 2) and LIM homeobox 1 family, SPAG4 (sperm associated antigen 4) and NKX3-1 (NK3 homeobox 1) in U87MG glioblastoma cells in response to inhibition of ERN1 (endoplasmic reticulum to nucleus signaling 1) for evaluation of their possible significance in the control of glioblastoma growth.

METHODS.

The expression level of homeobox genes was studied in control (transfected by vector) and ERN1 knockdown U87MG glioblastoma cells under hypoxia induced by dimethyloxalylglycine (0.5 mM for 4 h) by quantitative polymerase chain reaction and normalized to ACTB.

RESULTS.

It was found that hypoxia down-regulated the expression level of LHX2, LHX6, MEIS2, and NKX3-1 genes but up-regulated the expression level of MEIS1, LHX1, MEIS3, and SPAG4 genes in control glioblastoma cells. At the same time, ERN1 knockdown of glioblastoma cells significantly modified the sensitivity of all studied genes to a hypoxic condition. Thus, ERN1 knockdown of glioblastoma cells removed the effect of hypoxia on the expression of MEIS1 and LHX1 genes, but increased the sensitivity of MEIS2, LHX2, and LHX6 genes to hypoxia. However, the expression of MEIS3, NKX3-1, and SPAG4 genes had decreased sensitivity to hypoxia in ERN1 knockdown glioblastoma cells. Moreover, more pronounced changes under the conditions of ERN1 inhibition were detected for the pro-oncogenic gene SPAG4.

CONCLUSION.

The results of the present study demonstrate that hypoxia affected the expression of homeobox genes MEIS1, MEIS2, MEIS3, LHX1, LHX2, LHX6, SPAG4, and NKX3-1 in U87MG glioblastoma cells in gene-specific manner and that the sensitivity of all studied genes to hypoxia condition is mediated by ERN1, the major pathway of the endoplasmic reticulum stress signaling, and possibly contributed to the control of glioblastoma growth. A fundamentally new results of this work is the establishment of the fact regarding the dependence of hypoxic regulation of SPAG4 gene expression on ER stress, in particular ERN1, which is associated with suppression of cell proliferation and tumor growth.

Matrine restrains the development of colorectal cancer through regulating the AGRN/Wnt/β-catenin pathway

BACKGROUND

Colorectal cancer is a common malignant digestive tract tumor. This study aimed to explore the biological role and potential underlying mechanism of matrine in colorectal cancer.

METHODS

The mRNA expression of AGRN was measured using RT-qPCR. Cell proliferation, migration, invasion and apoptosis were determined using CCK-8, EdU, transwell assays and flow cytometry, respectively. Xenograft tumor experiment was performed to explore the action of matrine and AGRN on tumor growth in colorectal cancer in vivo. Immunohistochemistry (IHC) assay was applied for AGRN, β-catenin, and c-Myc expression in the tumor tissues from mice.

RESULTS

Matrine dramatically repressed cell growth and reduced the level of AGRN in colorectal cancer cells. AGRN expression was boosted colorectal cancer tissues and cells. AGRN downregulation depressed cell proliferation, migration, invasion, and enhanced cell apoptosis in colorectal cancer cells. Moreover, matrine showed the anti-tumor effects on colorectal cancer cells via regulating AGRN expression. AGRN knockdown could inactivate the Wnt/β-catenin pathway in colorectal cancer cells. We found that AGRN downregulation exhibited the inhibition action in the progression of colorectal cancer by modulating the Wnt/β-catenin pathway. In addition, matrine could inhibit the activation of the Wnt/β-catenin pathway through regulating AGRN in colorectal cancer cells. Furthermore, xenograft tumor experiment revealed that matrine treatment or AGRN knockdown repressed the development of colorectal cancer via the Wnt/β-catenin pathway in vivo.

CONCLUSION

Matrine retarded colorectal cancer development by modulating AGRN to inactivate the Wnt/β-catenin pathway.

Hsa_circ_0008726 regulates the proliferation, migration, and invasion of trophoblast cells in preeclampsia through modulating the miR-1290-LHX6 signaling pathway

Background

Preeclampsia (PE) is a serious complication of pregnancy, with a global incidence of about 2%–8%. It is one of the important causes of morbidity and mortality among the pregnant women and perinatal infants. Circular RNA (circRNA) has been confirmed to play an important regulatory role in PE. This study aimed to evaluate the role of hsa_circ_0008726 in the occurrence and development of PE.

Methods

The expression of hsa_circ_0008726 in PE placental tissue and blood was detected by qRT‐PCR. CCK‐8, wound closure, and Transwell assay were used to measure cell proliferation, migration, and invasion. Bioinformatics prediction, Western blotting, and dual‐luciferase reporter gene detection were used to explore the mechanism of hsa_circ_0008726 in HTR8/SVneo cells.

Results

The expression level of circ_0008726 in the placental tissue and blood samples of PE patients was significantly higher than that of normal controls. The overexpression of circ_0008726 can significantly inhibit the proliferation, migration, and invasion ability of HTR‐8/SVneo cells. While the silence of circ_0008726 showed an opposite effect. Furthermore, hsa_circ_0008726 can modulate the expression of LHX6 by adsorbing miR‐1290.

Conclusion

Hsa_circ_000872 can regulate LHX6 by adsorbing miR‐1290 to inhibit PE progression, thus establishing hsa_circ_000872 as a potential target for predicting and treating PE.