Circular RNA circDVL1 inhibits clear cell renal cell carcinoma progression through the miR-412-3p/PCDH7 axis

Clear cell renal cell carcinoma (ccRCC) is a primary kidney cancer with high aggressive phenotype and extremely poor prognosis. Accumulating evidence suggests that circular RNAs (circRNAs) play pivotal roles in the occurrence and development of various human cancers. However, the expression, clinical significance and regulatory role of circRNAs in ccRCC remain largely unclear. Here we report that circDVL1 to be reduced in the serums and tissues from ccRCC patients, and to negatively correlate with ccRCC malignant features. Overexpression of circDVL1 inhibits proliferation, induces G1/S arrest, triggers apoptosis, and reduces migration and invasion in different ccRCC cells in vitro. Correspondingly, circDVL1 overexpression suppresses ccRCC tumorigenicity in a mouse xenograft model. Mechanistically, circDVL1 serves as a sponge for oncogenic miR-412-3p, thereby preventing miR-412-3p-mediated repression of its target protocadherin 7 (PCDH7) in ccRCC cells. Collectively, our results demonstrate that circDVL1 exerts tumor-suppressive function during ccRCC progression through circDVL1/miR-412-3p/PCDH7 axis, and suggest that circDVL1 could be a novel diagnostic and prognositc marker and therapeutic target for ccRCC.     

Pseudogene HSPB1P1 contributes to renal cell carcinoma proliferation and metastasis by targeting miR-296-5p to regulate HMGA1 expression

With the aid of next-generation sequencing technology, pseudogenes have been widely recognized as functional regulators in the development and progression of certain diseases, especially cancer. Our present study aimed to investigate the functions and molecular mechanisms of HSPB1-associated protein 1 pseudogene 1 (HSPB1P1) in renal cell carcinoma (RCC). HSPB1P1 expression at the mRNA levels was determined by quantitative real-time polymerase chain reaction, and its clinical significance was assessed. Cell viability was detected by Cell Counting Kit-8 assay. Cell migration and invasion were detected by transwell assays. The location of HSPB1P1 in RCC cells was detected by subcellular distribution analysis. The direct relationship between HSPB1P1 and miR-296-5p/HMGA1 axis was verified by dual-luciferase reporter assay and RNA immunoprecipitation assay. Our results identify the elevated expression of HSPB1P1 in RCC tissues and cell lines, which predicted advanced progression and poor prognosis in patients with RCC. Knockdown of HSPB1P1 suppressed cell proliferation, migration, and invasion, and reversed epithelial–mesenchymal transition process in RCC. HSPB1P1 was mostly enriched in the cytoplasm and functioned as a miRNA sponge for miR-296-5p and then regulated high-mobility group A1 expression. In conclusion, our study indicated that HSPB1P1 contributed to RCC progression by targeting the miR-296-5p/HMGA1 axis, and should be considered as a promising biomarker and therapeutic target for clinical applications.     

LncRNA-UCA1 modulates progression of colon cancer through regulating the miR-28-5p/HOXB3 axis

Emerging evidence has shown that the long noncoding RNA urothelial carcinoma–associated 1 (UCA1) plays a tumor-promoting role in colorectal cancer, while miR-28-5p shows tumor-inhibitory activity in several tumor types. However, the mechanisms both of these in colon cancer progression are still unknown. In this work, the detailed roles and mechanisms of UCA1 and its target genes in colon cancer were studied. The results showed that UCA1 was upregulated in colon cancer tissues when compared with the adjacent nonhumorous tissues, as well as in the various colon cancer cell lines, but the expression of miR-28-5p showed an opposite trend. Furthermore, a high UCA1 level in colon cancer tissues is positively associated with the tumor size and advanced tumor stages. Functional assays revealed that both UCA1 knockdown and miR-28-5p overexpression could inhibit colon cancer cell growth and migration. Further mechanistic studies indicated that UCA1 knockdown played tumor suppressive roles in SW480 and HT116 cells through binding with miR-28-5p. We also, for the first time, identified HOXB3 as the target gene of miR-28-5p and that HOXB3 overexpression could mediate the functions of UCA1 in cell proliferation and migration of colon cancer cells. In conclusion, our data provided evidence for the regulatory network of UCA1/miR-28-5p/HOXB3 in colon cancer, suggesting that UCA1, miR-28-5p, and HOXB3 are the potential targets for colon cancer therapy.     

Nobiletin inhibits hypoxia-induced epithelial-mesenchymal transition in renal cell carcinoma cells

Hypoxia is a universal characteristic of solid tumor and involving cancer metastasis via epithelial-mesenchymal transition (EMT). Nobiletin (3′,4′,5,6,7,8-hexamethoxyflavone), a dietary polymethoxylated flavonoid found in citrus fruits, has been reported to have anticancer effects. However, the possible role of nobiletin in renal cell carcinoma (RCC) remains unclear. Thus, the aim of this study was to identify the effect of nobiletin on hypoxia-induced EMT in RCC cells. We found that nobiletin significantly inhibited the migration and invasion induced by hypoxia in RCC cells. In addition, nobiletin reversed the hypoxia-induced EMT process in RCC cells. Furthermore, nobiletin suppressed the activation of NF-κB and Wnt/β-catenin signaling pathways in hypoxia-stimulated RCC cells. In conclusion, these findings demonstrate that nobiletin inhibits hypoxia-induced EMT in human RCC cells via the inactivation of the NF-κB and Wnt/β-catenin signaling pathways.     

Circular RNA hsa_circRNA_103809 promoted hepatocellular carcinoma development by regulating miR-377-3p/FGFR1/ERK axis

In the last decade, circular RNAs (circRNAs) emerge as important regulators in multiple biological processes. Lately, it is reported hsa_circRNA_103809 could play vital parts in several types of cancers. Based on the analysis of GEO data (GSE97332), hsa_circRNA_103809 was found to be dysregulated in hepatocellular carcinoma (HCC). However, the biological function and underlying regulatory mechanisms of hsa_circRNA_103809 in HCC remain unclear. Our results suggested that hsa_circRNA_103809 was overexpressed in HCC patients, and hsa_circRNA_103809 knockdown remarkably inhibited the proliferation, cycle progression, and migration of HCC cells. The investigations of molecular showed that hsa_circRNA_103809 could elevate the protein expression of a miR-377-3p target, fibroblast growth factor receptor 1 (FGFR1), through interacting with miR-377-3p and decreasing its expression level. Additionally, in vivo assays revealed hsa_circRNA_103809 short hairpin RNA served as a tumor suppressor through downregulating FGFR1 in HCC. This study systematically investigated novel regulatory signaling of hsa_circRNA_103809/miR-377-3p/FGFR1 axis, providing insights into hepatocellular carcinoma treatment from bench to clinic.     

miR-143 inhibits proliferation and metastasis of nasopharyngeal carcinoma cells via targeting FMNL1 based on clinical and radiologic findings

Mounting evidence has reported that microRNA-143 (miR-143) is involved in the development of multiple cancers. To investigate the underlying mechanisms of miR-143 regulating proliferation and metastasis in nasopharyngeal carcinoma (NPC) cells, we evaluated the levels of miR-143 and formin-like protein 1 (FMNL1) in NPC tissues. The results of qRT-PCR and Western blot analysis showed that the expression of miR-143 was decreased, while FMNL1 was increased in NPC tissues. The expression of miR-143 was significantly elevated in NPC cells compared with that of human nasopharyngeal epithelial cells. The results of MiRcode prediction, dual-luciferase reporter, and Western blot analysis assays indicated that miR-143 negatively regulated the expression of FMNL1 (r² = 0.4365P = 0.0001). Overexperssion of miR-143 or FMNL1 knockdown inhibited cell proliferation, migration, and invasion in NPC cells (P < 0.05). Ectopic expression of FMNL1 undermined the inhibition effect of miR-143 on proliferation, migration, and invasion in NPC cells. The findings of this study revealed that miR-143 functioned as a tumor suppressor and inhibited the NPC progression by targeting FMNL1.     

Melatonin ameliorates renal fibroblast-myofibroblast transdifferentiation and renal fibrosis through miR-21-5p regulation

Fibroblast-myofibroblast transdifferentiation (FMT) is widely recognized as the major pathological feature of renal fibrosis. Although melatonin has exerted antifibrogenic activity in many diseases, its role in renal FMT remains unclear. In the present study, the aim was to explore the effect of melatonin on renal FMT and the underlying mechanisms. We established the transforming growth factor (TGF)-β1 stimulated rat renal fibroblast cells (NRK-49F) model in vitro and unilateral ureteral obstruction (UUO) mice model in vivo. We assessed levels of α-smooth muscle actin (α-SMA), col1a1 and fibronectin, STAT3 and AP-1, as well as miR-21-5p and its target genes (Spry1, PTEN, Smurf2 and PDCD4). We found that melatonin reduced the expression of α-SMA, col1a1 and fibronectin, as well as the formation of α-SMA filament in TGF-β1-treated NRK-49F cells. Meanwhile, melatonin inhibited STAT3 phosphorylation, down-regulated miR-21-5p expression, and up-regulated Spry1 and PTEN expression. Moreover, miR-21-5p mimics partially antagonized the anti-fibrotic effect of melatonin. For animal experiments, the results revealed that melatonin remarkably ameliorated UUO-induced renal fibrosis, attenuated the expression of miR-21-5p and pro-fibrotic proteins and elevated Spry1 and PTEN expression. Nevertheless, agomir of miR-21-5p blocked the renoprotective effect of melatonin in UUO mice. These results indicated that melatonin could alleviate TGF-β1-induced renal FMT and UUO-induced renal fibrosis through down-regulation of miR-21-5p. Regulation of miR-21-5p/PTEN and/or miR-21-5p/Spry1 signal might be involved in the anti-fibrotic effect of melatonin in the kidneys of UUO mice.     

miR-224-5p inhibits proliferation,migration, and invasion by targeting PIK3R3/AKT3 in uveal melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Accumulating investigations have identified the aberrant expression of miRNAs (microRNAs) in UM, such as miR-181, miR-20a, miR-144, miR-146a. The purpose of this study is to investigate the biological function of miR-224-5p in UM. The expression of miR-224-5p, PIK3R3, and AKT3 in 30 tumor tissues and paired adjacent noncancerous tissues were analyzed using Western blot analysis and quantitative real-time polymerase chain reaction (qRT-PCR) assays. Cell proliferation assay, transwell assay, and wound healing assay were used to measure the effects of miR-224-5p on the motility of UM in vitro. Western blot analysis and luciferase assays were used to detect the expression of PIK3R3 and AKT3 as miR-224-5p downstream targets. The results of Western blot analysis and qRT-PCR assays indicated that the expression of miR-224-5p was lower in UM tissues compared to normal tissue, while the expression of PIK3R3 and AKT3 were simultaneously increased. Upregulation of miR-224-5p significantly inhibited capacities of proliferation, invasion, and migration of OCM-1A cells and decreased expression of PIK3R3 and AKT3. Luciferase assay demonstrated PIK3R3 and AKT3 as downstream targets of miR-224-5p. Moreover, upregulating PIK3R3 and AKT3 restrained miR-224-5p-induced inhibition of the motility of OCM-1A cells. Thus, our study proved that miR-224-5p was involved in proliferation, invasion, and migration of UM cells via regulation the expression of PIK3R3 and AKT3. And the results also established a miR-224-5p/PIK3R3/PI3K/AKT axis in the regulation of UM progression, providing an experimental basis for further exploring the miR-224-5p as a therapeutic and diagnosis target for patients with UM.     

Pinin acts as a poor prognostic indicator for renal cell carcinoma by reducing apoptosis and promoting cell migration and invasion

Pinin (PNN) was originally characterized as a desmosome-associated molecule. Its function and the mechanism of its regulation in renal cell carcinoma (RCC) are still undefined. Data on PNN expression, clinicopathological features, and prognosis of patients with RCC were obtained from The Cancer Genome Atlas (TCGA) database. Immunohistochemistry revealed high PNN expression in tumour cells. PNN expression showed negative correlation with survival in patients with RCC, acting as an independent prognostic factor in RCC. PNN up-regulation might be attributed to epigenetic alterations in RCC. Immunofluorescence revealed PNN expression mainly in the nucleus of RCC cells. The transfection of siRNA targeting the PNN gene resulted in enhanced apoptosis, which was detected by flow cytometry, and reduced cell migration and invasion, which were assessed using wound healing and transwell migration assay. Gene set enrichment analysis revealed associations between PNN expression and several signalling pathways involved in cancer progression, as a potential mechanism underlying the carcinogenicity of PNN. The analyses of the Tumor Immune Estimation Resource platform showed significant positive associations between high PNN expression and tumour immune infiltrating cells. PNN may function as an oncogenic factor by reducing apoptosis and promoting cell migration and invasion in RCC.     

5-FU inhibits migration and invasion of CRC cells through PI3K/AKT pathway regulated by MARCH1

Colorectal cancer is a major health problem with a significant impact on the patients' quality of life. 5-Fluorouracil is the most common chemotherapy drug used for this type of cancer. While its molecular mechanism is the inhibition of DNA synthesis via the inhibition of thymine nucleotide synthetase, its complete anticancer mechanism is not clear. Membrane-associated RING-CH-1 (MARCH1) is an E3 ubiquitin ligase that plays an important role in antigen presentation. However, MARCH1 has not been studied in the context of colorectal cancer. In this study, we demonstrated that MARCH1 is highly expressed in colorectal cancer tissues and cell lines. Furthermore, migration and invasion of colorectal tumor cells were inhibited via transfection with small interfering RNAs to suppress the expression of MARCH1. The western blot analysis showed that MARCH1 regulates epithelial–mesenchymal transition and the PI3K/AKT pathway. Moreover, 5-fluorouracil inhibited the proliferation, migration, and invasion of tumor cells, via the targeting of MARCH1 and the consequent downregulation of the PI3K/AKT pathway, impacting the progression of epithelial–mesenchymal transition. In conclusion, our study shows that MARCH1 may play a role as an oncogene in colorectal cancer and may represent a new target molecule of 5-fluorouracil.     

MiR-490-5p inhibits the stemness of hepatocellular carcinoma cells by targeting ECT2

To explore the targeting relationship between miR-490-5p and ECT2 in hepatocellular carcinoma (HCC) and the influences of miR-490-5p and ECT2 on the stemness of HCC cells. The expressions of miR-490-5p and ECT2 in HCC tissues and adjacent tissues were identified by quantitative real-time polymerase chain reaction (qRT-PCR). The relationships between the expression levels of miR-490-5p/ ECT2 and the overall/disease-free survival (OS/DFS) of patients with HCC were evaluated using correlative curves. In addition, the targeting relationship between miR-490-5p and ECT2 was predicted by TargetScan and verified by dual-luciferase reporter assay. Plasmid transfection was used for overexpression of ECT2 in HepG2 cells, and transfection efficiency was verified by qRT-PCR. Cell Counting Kit-8 assay and cell sphere-formation assay were conducted to detect the proliferation and sphere-formation ability of HCC cells, respectively. Cell populations with different cell transfections were sorted using flow cytometry. The expression levels of proteins in the stem cell signaling pathway were determined using Western blot analysis. MiR-490-5p was remarkably downregulated, yet ECT2 was upregulated in HCC tissues compared with adjacent tissues. MiR-490-5p expression was positively correlated with OS and DFS of patients with HCC, which were otherwise negatively correlated with ECT2 expression. ECT2 was validated to be the downstream target of miR-490-5p. Overexpression of miR-490-5p restrained the sphere formation ability, stemness, and proliferation of HCC cells. MiR-490-5p repressed the stemness of HCC cells through inhibiting the expression of ECT2. MiR-490-5p may be an underlying therapeutic target in HCC treatment.     

Hsa_circ_0003596 enhances the development of cell renal clear cell carcinoma through the miR-502-5p/IGF1/PI3K/AKT axis

Accumulating research findings have shown that circular RNAs (circRNAs) play an indispensable role in tumorigenesis and tumor progression. The current study aimed to explore the role and modulatory mechanism of hsa_circ_0003596 in clear cell renal cell carcinoma (ccRCC). Quantitative real-time polymerase chain reaction was adopted to detect the expression of hsa_circ_0003596 in ccRCC tissue and cell lines. 5-Ethynyl-2′-deoxyuridine, cell counting kit 8 and the colony formation assay were utilized to assess the proliferation potential of the ccRCC cells. Transwell along with wound healing assays were adopted to quantify infiltration coupled with the migration potential of the cells. The current research study found that the circRNA hsa_circ_0003596 was overexpressed in ccRCC tissue and cell lines. Further, result showed that hsa_circ_0003596 was associated with distant metastasis of renal cancer. Notably, the knockdown of hsa_circ_0003596 can lower the proliferation, infiltration and migration potential of ccRCC cells. The results of in vivo experiments found that the reduction of hsa_circ_0003596 significantly hampered the growth of tumors in mice. In addition, it was evident that hsa_circ_0003596 acts as a “molecular sponge” for miR-502-5p to upregulate the expression of the microRNA-502-5p (miR-502-5p) target insulin-like growth factor 1 (IGF1R). Furthermore, it was found that the phosphatidylinositol 3-kinase (PI3K)/AKT signaling was the downstream cascade of hsa_circ_0003596/miR-502-5p/IGF1R cascade, which is partly responsible for the cancer-promoting effect. Overall, the results of the present study showed that hsa_circ_0003596 facilitated the proliferation, infiltration and migration of ccRCC through the miR-502-5p/IGF1R/PI3K/AKT axis. Therefore, it was evident that hsa_circ_0003596 can serve as a possible biomarker and therapeutic target against ccRCC.     

CircTIMELESS regulates the proliferation and invasion of lung squamous cell carcinoma cells via the miR-136-5p/ROCK1 axis

Numerous studies demonstrate that circular RNAs (circRNAs) are critical regulators of the occurrence and progression of tumors. However, research on the involvement of circRNAs in lung squamous cell carcinoma (LUSC) is limited. In our study, circTIMELESS (also named hsa_circ_0000408 in the Human circRNA Database) was upregulated in both LUSC tissues and LUSC cells, and circTIMELESS expression was positively associated with the TNM stage. Moreover, circTIMELESS silencing markedly suppressed invasion in vitro and disrupted proliferation in vitro as well as in vivo. Additional investigations have shown that circTIMELESS functions as a miR-136-5p “sponge” and regulates miR-136-5p expression. Furthermore, the impact of miR-136-5p upregulation was consistent with the results of circTIMELESS silencing, both of which inhibited the proliferation and invasion of LUSC cells. Additional results showed that Rho-associated coiled-coil containing protein kinase 1 (ROCK1) is targeted by miR-136-5p. The results of recovery experiments showed that ROCK1 overexpression partly rescued the impact of circTIMELESS silencing and miR-136-5p upregulation on proliferation and invasion. Consequently, our findings confirmed that circTIMELESS exists in LUSC and acts as a tumor promoter through the miR-136-5p/ROCK1 axis. Based on these findings, circTIMELESS may be potentially utilized as a therapeutic target for LUSC.