DOK7, a target of miR-299-5p, suppresses the progression of bladder cancer

OBJECTIVE

Bladder cancer (BLCA) is the 6th most common malignancy in males. microRNA (miRNAs) can function as tumor suppressors or oncogenic factors, which are of significance in the progression of BLCA. This study explored the mechanisms by which miR-299-5p modulates DOK7 (Docking Protein 7) expression and the functional role of DOK7 in the progression of BLCA.

METHODS

The expression of the DOK7 in BLCA patient samples was examined by RT-qPCR (Real-time quantitative polymerase chain reaction), Western blotting and Immunohistochemical (IHC) staining. The malignant phenotype of BLCA cells upon DOK7 overexpression or silencing was assessed by functional assays including cell count kit-9 (CCK8), colony formation and 5-ethynyl-2'-deoxyuridine (Edu) staining assays, as well as Transwell migration and invasion assays. The miRNA regulators of DOK7 were identified through bioinformatics prediction, and the biological role of miR-299-5p/DOK7 axis was validated by functional assays. The impact of miR-299-5p/DOK7 axis on Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway was further examined by Western blotting.

RESULTS

DOX7 was significantly downregulated in BLCA tumor tissues compared with normal tissues. Ectopic DOK7 expression suppressed the proliferation, migration and invasion of BLCA cells. DOK7 overexpression also attenuated the tumorigenesis of BLCA cells in nude mice. miR-299-5p was a negative regulator of DOK7 expression in BLCA cells. miR-299-5p/DOK7 axis impaired the malignancy of BLCA cells through regulating the JAK signaling pathway.

CONCLUSION

Our data indicate that miR-299-5p/DOK7 axis suppresses BLCA progression possibly by regulating the JAK signaling pathway.

LINC00467 enhances head and neck squamous cell carcinoma progression and the epithelial-mesenchymal transition process via miR-299-5p/ubiquitin specific protease-48 axis

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) has attracted the attention of researchers as a result of its high incidence around the world. This malignancy occurs in the oral cavity, pharynx and larynx in most cases. A number of lncRNAs have been revealed to regulate the malignant neoplasia of several cancers. Nevertheless, the effects of lncRNA LINC00467 in HNSCC have not yet been reported.

METHODS

The expression of LINC00467, miR-299-5p and ubiquitin specific protease-48 (USP48) in HNSCC cells was quantified by a quantitative reverse transcriptase-polymerase chain reaction. The influences of LINC00467 deficiency on HNSCC progression were reflected by cell counting kit-8, colony formation, ethynyl-2-deoxyuridine, wound healing and western blot assays. RIP and luciferase reporter assays were conducted to confirm the interaction among LINC00467, miR-299-5p and USP48.

RESULTS

LINC00467 was considerably upregulated in HNSCC cells, and an absence of LINC00467 suppressed cell growth, cell migration and the epithelial-mesenchymal process in HNSCC. In addition, miR-299-5p expression was notably downregulated in HNSCC cells, and miR-299-5p could bind with LINC00467. Furthermore, USP48 was conspicuously overexpressed in HNSCC cells and capable of binding with miR-299-5p. LINC00467 could upregulate USP48 expression via sponging miR-299-5p. Finally, rescue assays proved that USP48 overexpression could compensate for the suppressive effects on HNSCC progression mediated by LINC00467 deficiency.

CONCLUSIONS

LINC00467 enhances HNSCC progression by serving as a sponge of miR-299-5p to increase USP48 expression.

Periodontal ligament cells regulate osteogenesis via miR-299-5p in mesenchymal stem cells

BACKGROUND

The periodontal ligament contains periodontal ligament cells, which is a heterogeneous cell population, and includes progenitor cells that can differentiate into osteoblasts/cementoblasts. Mesenchymal stem cells (MSCs) can differentiate into various cells and can be used for periodontal regenerative therapy. Therefore, transplanted MSCs can be affected by humoral factors from periodontal ligament cells via the transcription factors or microRNAs (miRNAs) of MSCs. In addition, periostin (POSTN) is secreted from HPL cells and can regulate periodontal regeneration and homeostasis. To clarify the regulatory mechanism of humoral factors from periodontal ligament cells, we attempted to identify key genes, specifically microRNAs, involved in this process.

METHODS

Human MSCs (hMSCs) were indirectly co-cultured with human periodontal ligament cells (HPL cells) and then evaluated for osteogenesis, undifferentiated MSCs markers, and miRNA profiles. Furthermore, hMSCs were indirectly co-cultured with HPL cells in the presence of anti-POSTN monoclonal antibody (anti-POSTN Ab) to block the effect of POSTN from HPL cells, and then evaluated for osteogenesis or undifferentiated MSC markers. Moreover, hMSCs showed alterations in miRNA expression or cultured with HPL were challenged with POSTN during osteogenesis, and cells were evaluated for osteogenesis or undifferentiated MSC markers.

RESULTS

hMSCs co-cultured with HPL cells showed suppressed osteogenesis and characteristic expression of SOX11, an undifferentiated MSC marker, as well as miR-299-5p. Overexpression of miR-299-5p regulated osteogenesis and SOX11 expression as observed with indirect co-culture with HPL cells. Furthermore, MSCs co-cultured with HPL cells were recovered from the suppression of osteogenesis and SOX11 mRNA expression by anti-POSTN Ab. However, POSTN induced miR-299-5p and SOX11 expression, and enhanced osteogenesis.

CONCLUSION

Humoral factors from HPL cells suppressed osteogenesis in hMSCs. The suppressive effect was mediated by miR-299-5p and SOX11 in hMSCs.

miRNA-299-5p regulates estrogen receptor alpha and inhibits migration and invasion of papillary thyroid cancer cell

Background

The incidence of papillary thyroid cancer (PTC) is increasing faster than any other solid tumors worldwide. Invasion and metastasis are the main reasons for the poor prognosis of patients with PTC. Previously, we observed significantly low expression of miRNA-299-5p in invasive PTC tissue samples.

Aim

The present study aimed to determine whether miR-299-5p plays a key role in PTC migration and invasion.

Materials and methods

The miR-299-5p expression level was measured using quantitative real-time PCR in 109 human PTC samples and paired adjacent normal tissues and in the human BCPAP PTC cell line. The effects of miR-299-5p on PTC cell migration and invasion were assessed using wound healing and transwell assays. In addition, we searched for the miR-299-5p target, and the potential mechanism was demonstrated using a reporter assay and rescue experiment.

Results

The expression of miR-299-5p was associated with gender and extrathyroidal extension, and an elevated level of miR-299-5p suppressed BCPAP cell migration and invasion. Estrogen receptor α (ERα) is a direct target of miR-299-5p. The expression level of ERα was significantly higher in PTC tissues and was associated with migration and invasion in PTC cells. Overexpression of ERα could impair miR-299-5p-induced inhibition of migration and invasion. As a key factor of the pathway related to PTC invasion, Gli1 can be combined with ERα and can be regulated by miR-299-5p.

Conclusion

Our data suggested that miR-299-5p could participate in PTC migration and invasion and could be a potential therapeutic target for patients with aggressive PTC tumors.

Inhibition of microRNA-299-5p sensitizes glioblastoma cells to temozolomide via the MAPK/ERK signaling pathway

Glioblastomas (GBMs) are a lethal class of brain cancer, with a median survival <15 months in spite of therapeutic advances. The poor prognosis of GBM is largely attributed to acquired chemotherapy resistance, and new strategies are urgently needed to target resistant glioma cells. Here we report a role for miR-299-5p in GBM. The level of miR-299-5p expression was detected in glioma specimens and cell lines by qRT-PCR. Luciferase reporter assays and Western blots were performed to verify GOLPH3 as a direct target of miR-299-5p. In vitro cell proliferation, invasion, cell cycle distribution, and apoptosis were assessed to determine whether or not miR-299-5p knockdown sensitized GBM cells to temozolomide (TMZ). We demonstrated that miR-299-5p levels were up-regulated in the GBM groups compared with the normal control group. The highest expression of miR-129-5p occurred in the highest GBM stage. miR-299-5p knockdown significantly inhibited the MAPK/extracellular signal-regulated kinase (ERK) signaling pathway. We also showed that miR-299-5p knockdown enhanced sensitivity of GBM cells to TMZ both in vitro and in vivo by inhibiting cell proliferation and invasion and promoting apoptosis. In addition, we demonstrated that GOLPH3 is a novel functional target of miR-299-5p GOLPH3 regulates the MAPK/ERK axis under miR-299-5p regulation. In conclusion, we identified a link between miR-299-5p expression and the GOLPH3/MAPK/ERK axis, thus illustrating a novel role for miR-299-5p in GBM.

Importance of miR-299-5p in colorectal cancer

Background

MicroRNAs (miRNAs) are effective regulators of gene expression that play a pivotal role in the pathogenesis of colorectal cancer (CRC) and various other cancers. The high prevalence of aberrant miRNA expression in CRC suggests that they can be used as biomarkers and anticancer molecules for therapeutic purposes. There is evidence that microRNA-299-5p (miR-299-5p) is associated with vital cell processes (e.g. epithelial-mesenchymal transition, proliferation, and tumorigenicity) and its improper expression with tumorigenesis in many types of human cancer. This prospective study investigated the contribution of miR-299-5p to CRC tumorigenesis.

Methods

The real-time reverse transcription-polymerase chain reaction was used to examine miR-299-5p expression levels prospectively in 40 sample pairs of CRC tissue and adjacent noncancerous tissue (>2 cm from cancer tissue). The ability of miR-299-5p to function as a tumor marker was also examined.

Results

The expression levels of miR-299-5p were significantly downregulated in the group of CRC samples compared with matched noncancerous tissue samples. No significant relationship was found between miR-299-5p expression levels and clinicopathological features. Receiver operating characteristic analysis gave an area under the curve of 71% for miR-299-5p with 68% sensitivity and 78% specificity (P=0.001).

Conclusion

The miRNA miR-299-5p may be considered as a tumor marker in CRC and could be of assistance as a potential predictive biomarker in the diagnosis of this cancer.

The Value of miR-299-5p in Diagnosis and Prognosis of Intestinal-Type Gastric Adenocarcinoma

MicroRNAs (miRNAs) are a class of non-coding RNAs, containing about 22 nucleotides and having a pivotal function in various cellular processes. The oncogenic and tumor suppressor roles of miRNAs have been identified in cancers especially in gastric cancer, which is one of the most prevalent cancers. MiR-299-5p is located in the imprinted Dlk1-Dio3 region in chromosome 14q32. Aberrant expression of miR-299-5p was determined in solid and blood cancers. The current study was performed to assess the expression pattern of miR-299-5p in intestinal-type gastric adenocarcinoma and compare it with the normal adjacent counterparts. The expression level of miR-299-5p was investigated in forty fresh specimens which were obtained from gastric cancer patients during endoscopy. Moreover, the association of aberrant expression of miR-299-5p and clinicopathological features, as well as the susceptibility of miR-299-5p as a tumor marker, was determined. The result of qRT-PCR revealed the downregulation of miR-299-5p in intestinal-type gastric adenocarcinoma compared with adjacent tumor-free tissues (P < 0.001); this misregulation can be used as a tumor marker. Analysis of miR-299-5p misregulation did not reveal a significant correlation with clinical features. The result obtained from the present study revealed the significant downregulation of miR-299-5p in intestinal-type gastric adenocarcinoma which is consistent with previous studies showing miR-299-5p downregulation in other types of cancers. The data obtained from the current study suggest basic information which can be very helpful for future research in the field of diagnosis and treatment of gastric cancer.