Palbociclib sensitizes ER-positive breast cancer cells to fulvestrant by promoting the ubiquitin-mediated degradation of ER-α via SNHG17/Hippo-YAP axis

PURPOSE

Endocrine therapy is the anti-tumor therapy for human breast cancer but endocrine resistance was a major burden. It has been reported that Palbociclib and fulvestrant can be used in combination for the treatment of patients who are experiencing endocrine resistance. However, the underlying mechanism is unclear. In this study, we aimed to investigate the mechanism by which Palbocicilib affected ER-positive breast cancer, combined with fulvestrant.

METHODS

We first detected the effect of palbociclib on cell survival, growth and cycle distribution separately by MTT, colony formation and flow cytometry. Then SNHG17 was screened as palbociclib-targeted LncRNA by LncRNA-seq, and the SNHG17-targeted mRNAs were selected by mRNA-seq for further determination. Subsequently, the underlying mechanism by which palbociclib promoted the cytotoxicity of fulvestrant was confirmed by qRT-PCR, western blot, and immunoprecipitation. Eventually, the xenograft model and immunohistochemistry experiments were used to validate the sensitization effect of palbociclib on fulvestrant and its mechanism in vivo.

RESULTS

Palbociclib significantly enhanced the cytotoxicity of fulvestrant in fulvestrant-resistant breast cancer cell lines. Interestingly, this might be related to the lncRNA SNHG17 and the Hippo signaling pathway. And our subsequent western blotting experiments confirmed that overexpressing SNHG17 induced the down-regulation of LATS1 and up-regulated YAP expression. Furthermore, we found that the increased sensitivity of breast cancer cells was closely associated with the LATS1-mediated degradation of ER-α. The following animal experiments also indicated that overexpressing SNHG17 obviously impaired the anti-cancer effect of co-treatment of palbociclib and fulvestrant accompanied by decreased LATS1 and increased ER-α levels.

CONCLUSION

Palbociclib might sensitize the cytotoxicity of fulvestrant in ER-positive breast cancer cells by down-regulating SNHG17 expression, and then resulted in the LATS1-inactivated oncogene YAP and LATS1-mediated degradation of ER-α.

SNHG17 alters anaerobic glycolysis by resetting phosphorylation modification of PGK1 to foster pro-tumor macrophage formation in pancreatic ductal adenocarcinoma

BACKGROUND

Within the tumor immune microenvironment (TME), tumor-associated macrophages (TAMs) are crucial in modulating polarization states to influence cancer development through metabolic reprogramming. While long non-coding RNAs (lncRNAs) have been shown to play a pivotal role in the progression of various cancers, the underlying mechanisms by which lncRNAs alter M2 polarization through macrophage metabolism remodeling remain unelucidated.

METHODS

RNA sequencing was used to screen for differentially expressed lncRNAs in TAMs and normal tissue-resident macrophages (NTRMs) isolated from pancreatic ductal adenocarcinoma (PDAC) tissues, whilst RT-qPCR and FISH were employed to detect the expression level of SNHG17. Moreover, a series of in vivo and in vitro experiments were conducted to assess the functions of SNHG17 from TAMs in the polarization and glycolysis of M2-like macrophages and in the proliferation and metastasis of pancreatic cancer cells (PCs). Furthermore, Western blotting, RNA pull-down, mass spectrometry, RIP, and dual-luciferase assays were utilized to explore the underlying mechanism through which SNHG17 induces pro-tumor macrophage formation.

RESULTS

SNHG17 was substantially enriched in TAMs and was positively correlated with a worse prognosis in PDAC. Meanwhile, functional assays determined that SNHG17 promoted the malignant progression of PCs by enhancing M2 macrophage polarization and anaerobic glycolysis. Mechanistically, SNHG17 could sponge miR-628-5p to release PGK1 mRNA and concurrently interact with the PGK1 protein, activating the pro-tumorigenic function of PGK1 by enhancing phosphorylation at the T168A site of PGK1 through ERK1/2 recruitment. Lastly, SNHG17 knockdown could reverse the polarization status of macrophages in PDAC.

CONCLUSIONS

The present study illustrated the essential role of SNHG17 and its molecular mechanism in TAMs derived from PDAC, indicating that SNHG17 might be a viable target for PDAC immunotherapy.

Long non-coding RNA SNHG17 contributes to the progression of pancreatic adenocarcinoma by modulating miR-32-5p/EZH2/STAT3 signaling

BACKGROUND

Adenocarcinoma of the pancreas (PAAD) is one of the most malignant tumors in the gastrointestinal tract. Long-chain noncoding RNAs (lncRNAs) are non-coding RNAs that are expressed in a variety of cancers. The purpose of this study is to study the expression, biology functions, and molecular mechanism of lncRNA SNHG17 in PAAD.

METHODS

In this study, qRT-PCR was used to measure the relative expression of SNHG17 and miR-32-5p in PAAD. In order to investigate the effect of SNHG17 and miR-32-5p on the proliferation, migration and invasion of PAAD cells, we performed a variety of tests including CCK-8, colony formation, scratch and transwell assays. Furthermore, SNHG17 and miR-32-5p interactions were confirmed by a luciferase reporter gene test.

RESULTS

Our results indicate that the expression of SNHG17 in PAAD is elevated, and in vitro studies have shown that SNHG17 enhances the proliferation of PAAD cells, Mechanistically, it has been shown that SNHG17 can direct target miR-32-5p in PAAD cells, thus promoting the proliferation of PAAD cells, migration, and invasion. Furthermore, SNHG17 has been found to activate EZH2/STAT3 signaling pathway through miR-32-5p in PAAD cells.

CONCLUSION

Our results show that SNHG17 plays a key role in the progression of PAAD by activating STAT3 signaling via regulation of miR-32-5p and EZH2.Identifying these new regulatory pathways may shed light on the underlying mechanism of PAAD and offer a potential therapeutic target for this fatal disease.

Low SP1 SUMOylation-dependent SNHG17 upregulation promotes drug resistance of gastric cancer through impairing hsa-miR-23b-3p-induced Notch2 inhibition

OBJECTIVE

Specificity protein 1 (SP1), a transcription factor mediated by SUMOylation modifiers, is upregulated in gastric cancer (GC) and shares negative correlation with patient prognosis. Here, we paid main attention to the role of SP1 SUMOylation in the drug resistance of GC cells and the possible long non-coding RNA (lncRNA) SNHG17/microRNA-23b-3p (miR-23b-3p)/Notch2 network engaged in this process.

METHODS

Tumor tissues and non-tumor tissues were isolated from GC patients who received treatment with capecitabine and cisplatin (DDP). Co-immunoprecipitation was utilized to detect the SUMOylation level of SP1. Using gain- and loss-of-function approaches, we assessed the impacts of SNHG17/miR-23b-3p/Notch2 on sensitivity of DDP-resistant GC cells in vitro and in vivo. A series of assays such as luciferase activity detection and RNA pull-down were conducted for mechanistic exploration.

RESULTS

SP1 expression was increased due to low SP1 SUMOylation level in the recurrent GC tissues. This increase led to upregulated SNHG17 expression and SP1 binding sites existed in the SNHG17 promoter. In addition, SNHG17 could bind to miR-23b-3p while miR-23b-3p targeted Notch2. Loss of SNHG17 reduced the resistance of DDP-resistant GC cells to DDP, which was achieved through miR-23b-3p-dependent Notch2 inhibition. Finally, SP1 silencing attenuated the resistance of GC to DDP in mice.

CONCLUSION

Low SP1 SUMOylation induces SNHG17 upregulation and blocks miR-23b-3p-induced Notch2 inhibition, contributing to the resistance of GC to DDP. This study may aid in the development of therapeutic targets overcoming the chemoresistance of GC.

SNHG17 promotes colorectal tumorigenesis and metastasis via regulating Trim23-PES1 axis and miR-339-5p-FOSL2-SNHG17 positive feedback loop

Background

Small nucleolar RNA host gene (SNHG) long noncoding RNAs (lncRNAs) are frequently dysregulated in human cancers and involved in tumorigenesis and progression. SNHG17 has been reported as a candidate oncogene in several cancer types, however, its regulatory role in colorectal cancer (CRC) is unclear.

Methods

SNHG17 expression in multiple CRC cohorts was assessed by RT-qPCR or bioinformatic analyses. Cell viability was evaluated using Cell Counting Kit-8 (CCK-8) and colony formation assays. Cell mobility and invasiveness were assessed by Transwell assays. Tumor xenograft and metastasis models were applied to confirm the effects of SNHG17 on CRC tumorigenesis and metastasis in vivo. Immunohistochemistry staining was used to measure protein expression in cancer tissues. RNA pull-down, RNA immunoprecipitation, chromatin immunoprecipitation, and dual luciferase assays were used to investigate the molecular mechanism of SNHG17 in CRC.

Results

Using multiple cohorts, we confirmed that SNHG17 is aberrantly upregulated in CRC and correlated with poor survival. In vitro and in vivo functional assays indicated that SNHG17 facilitates CRC proliferation and metastasis. SNHG17 impedes PES1 degradation by inhibiting Trim23-mediated ubiquitination of PES1. SNHG17 upregulates FOSL2 by sponging miR-339-5p, and FOSL2 transcription activates SNHG17 expression, uncovering a SNHG17-miR-339-5p-FOSL2-SNHG17 positive feedback loop.

Conclusions

We identified SNHG17 as an oncogenic lncRNA in CRC and identified abnormal upregulation of SNHG17 as a prognostic risk factor for CRC. Our mechanistic investigations demonstrated, for the first time, that SNHG17 promotes tumor growth and metastasis through two different regulatory mechanisms, SNHG17-Trim23-PES1 axis and SNHG17-miR-339-5p-FOSL2-SNHG17 positive feedback loop, which may be exploited for CRC therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02162-8.

SNHG17, as an EMT-related lncRNA, promotes the expression of c-Myc by binding to c-Jun in esophageal squamous cell carcinoma

Dysregulation of long noncoding RNA SNHG17 is associated with the occurrence of several tumors; however, its role in esophageal squamous cell carcinoma (ESCC) remains obscure. The present study demonstrated that SNHG17 was upregulated in ESCC tissues and cell lines, induced by TGF‐β1, and associated with poor survival. It is also involved in the epithelial‐to‐mesenchymal transition (EMT) process. The mechanism underlying SNHG17‐regulated c‐Myc was detected by RNA immunoprecipitation, RNA pull‐down, chromatin immunoprecipitation, and luciferase reporter assays. SNHG17 was found to directly regulate c‐Myc transcription by binding to c‐Jun protein and recruiting the complex to specific sequences of the c‐Myc promoter region, thereby increasing its expression. Moreover, SNHG17 hyperactivation induced by TGF‐β1 results in PI3K/AKT pathway activation, promoting cells EMT, forming a positive feedback loop. Furthermore, SNHG17 facilitated ESCC tumor growth in vivo. Overall, this study demonstrated that the SNHG17/c‐Jun/c‐Myc axis aggravates ESCC progression and EMT induction by TGF‐β1 and may serve as a new therapeutic target for ESCC.

Long non-coding RNA SNHG17 promotes lung adenocarcinoma progression by targeting the microRNA-193a-5p/NETO2 axis

Long non-coding RNAs (lncRNAs) play vital roles in human cancers. It has been reported that lncRNA SNHG17 expression is dysregulated in different types of cancer and involved in cancer progression. However, the role of SNHG17 in lung adenocarcinoma (LUAD) remains unclear. The present study aimed to investigate the role of SNHG17 in LUAD. Reverse transcription-quantitative (RT-q) PCR analysis was performed to detect SNHG17 expression in LUAD tissues and cells. The effects of SNHG17 on cancer cell migration, invasion, proliferation and epithelial-to-mesenchymal transition (EMT) were assessed via Transwell, MTT and western blot assays, respectively. The interactions between SNHG17 and microRNA (miRNA/miR)-193a-5p, miR-193a-5p and neuropilin and tolloid-like 2 (NETO2) were assessed via the dual-luciferase reporter assay. NETO2 expression and its potential role in LUAD were analyzed via RT-qPCR analysis and the UALCAN database. The results demonstrated that SNHG17 expression was significantly upregulated in LUAD tissues and cells, and high SNHG17 expression was associated with tumor-node-metastasis stage and poor prognosis of patients with LUAD. SNHG17 knockdown inhibited cell migration, invasion, proliferation and the EMT process. In addition, the results revealed that SNHG17 functions as a competing endogenous RNA of miR-193a-5p. The results of the dual-luciferase reporter assay confirmed that miR-193a-5p can directly target SNHG17. NETO2 was also predicted as a target protein of miR-193a-5p, which was confirmed via the dual-luciferase reporter assay. The roles of NETO2 knockdown in cancer cells were rescued following transfection with miR-193a-5p inhibitor or overexpression of SNHG17. Notably, high NETO2 expression was associated with poor prognosis of patients with LUAD. Bioinformatics analysis demonstrated that the promoter methylation level of NETO2 decreased in LUAD. Taken together, the results of the present study suggest that SNHG17 expression is upregulated in LUAD tissues and cells, and SNHG17 exerts tumor promoting effect by targeting the miR-193a-5p/NETO2 axis.

LncRNA SNHG17 promotes tumor progression and predicts poor survival in human renal cell carcinoma via sponging miR-328-3p

Accumulating data shows that dysregulation of long non-coding RNAs (lncRNAs) are involved in human tumors' occurrence and progression. Small nucleolar RNA host genes (SNHGs) are recently revealed to play a carcinogenic role in various human neoplasms. However, the functions and underlying mechanisms of lncRNA SNHG17 in renal cell carcinoma (RCC) are still elusive. We analyzed the relationship between SNHG17 expression levels and clinicopathologic characteristics and prognosis in patients with RCC according to TCGA RNA-sequencing data and our cohort data. Loss-of-function and gain-of-function experiments were conducted to examine the biological behaviors of SNHG17 on RCC cell proliferation, migration, invasion, apoptosis, and tumor growth in vivo. The interaction between SNHG17, miR-328-3p, and Histone’sH2Avariant (H2AX) was verified by bioinformatics, dual-luciferase reporter gene, and RNA immunoprecipitation (RIP). Highly expressed SNHG17 was evident in RCC tissue samples and cell lines, and SNHG17 overexpression was related to advanced TNM stage and reduced relapse-free and overall survival of patients with RCC. Knockdown of SNHG17 prohibited malignant phenotypes, whereas ectopic SNHG17 expression showed the opposite effects. More importantly, SNHG17 could upregulate the expression of H2AX by acting as a miR-328-3p sponge. In vivo experiments confirmed that SNHG17 promoted the growth of RCC tumors. SNHG17/miR-328-3p/H2AXaxis might be involved in RCC progression, which provided a potential therapeutic target for RCC.

SNHG17 Serves as an Oncogenic lncRNA by Regulating the miR-361-3p/STC2 Axis in Rectal Cancer

Long noncoding RNA (lncRNA) have been reported to be crucial regulators for carcinogenesis, including rectal cancer. This work aimed to explore the roles and associated mechanisms of small nucleolar RNA host gene 17 (SNHG17) in rectal cancer. A quantitative real-time polymerase chain reaction was performed to measure the expression level of SNHG17 in rectal cancer tissues and cells. Cell counting kit-8 (CCK-8) assay and flow cytometry assay were conducted to measure the biological roles of SNHG17 in rectal cancer. In addition, luciferase activity reporter assay, RNA immunoprecipitation (RIP) assay, and rescue experiments were conducted to explore the mechanisms of SNHG17 in rectal cancer. The upregulation status of SNHG17 was identified in rectal cancer tissues and cells. Functionally, knockdown the expression of SNHG17 inhibits rectal cancer cell proliferation via stimulating cell apoptosis. In vivo assay showed that the knockdown of SNHG17 inhibits tumor growth. Furthermore, we showed that microRNA-361-3p (miR-361-3p) has decreased expression in tumor tissues and cells, and SNHG17 functions as a sponge for miR-361-3p. The upregulation status of stanniocalcin 2 (STC2) was also found in rectal cancer, and the knockdown of STC2 hinders cancer progression. In conclusion, lncRNA SNHG17 functions as an oncogenic lncRNA in rectal cancer by regulating the miR-361-3p/STC2 axis.

Long non-coding RNA SNHG17 enhances the aggressiveness of C4-2 human prostate cancer cells in association with β-catenin signaling

Long non-coding (lnc) RNAs have emerged as important regulators of cancer development and progression. Several lncRNAs have been reported to be associated with prostate cancer (PCa); however, the involvement of lncRNA SNHG17 in PCa remains unclear. In the present study, the mRNA expression level of SNHG17 in 58 pairs of PCa tumor samples and adjacent non-tumor tissues, as well as in PCa tumor cell lines was analyzed. The regulatory effect of SNHG17 on the oncogenic phenotypes of the C4-2 tumor cell line was also investigated. The clinicopathological analysis revealed that SNHG17 mRNA expression level was increased in the PCa tumor samples, and its high expression levels were associated with poor patient outcomes, indicating that SNHG17 may act as a biomarker for the prognosis of PCa. SNHG17 mRNA expression level was also increased in different PCa tumor cell lines. Functionally, SNHG17 increased C4-2 tumor cell growth and aggressiveness by stimulating tumor cell proliferation, survival, invasion and resistance to chemotherapy. Furthermore, SNHG17 promoted in vivo tumor growth in a xenograft mouse model. Notably, the SNHG17-induced in vitro and in vivo oncogenic effects were associated with activation of the β-catenin pathway. The results from the present study revealed that lncRNA SNHG17 could be an important regulator in the oncogenic properties of human PCa and may; therefore, represent a potential PCa therapeutic target.

lncRNA SNHG17 promotes pancreatic carcinoma progression via cross-talking with miR-942

OBJECTIVE

Long non-coding RNA (lncRNA) SNHG17 has been shown to modulate the biological behavior of multiple cancers (e.g., colorectal and lung cancers). However, its involvement in pancreatic cancer (PC) has not been explored; therefore, in the present study, we sought to examine this involvement.

METHODS

First, the mRNA expression levels of various genes were quantified in PC tissues and cell lines using quantitative reverse-transcription PCR (qRT-PCR). The interaction between SNHG17 and miR-942 was explored by bioinformatics prediction as well as a dual luciferase reporter assay. The proliferation and viability of pancreatic carcinoma cells were examined using cell counting kit-8 and MTT assays, respectively. Cellular migratory and invasive properties were evaluated using transwell migration and wound healing assays. Cell death was measured using flow cytometry. Protein expression was quantified by western blotting.

RESULTS

SNHG17 expression was markedly higher in human PC specimens and cell lines than in normal healthy tissues and pancreatic epithelial cells. MiR-942 expression displayed the opposite trend. Bioinformatics prediction and a dual luciferase reporter assay confirmed that SNHG17 serves as a sponge for miR-942. Loss-of-function assay revealed that SNHG17 silencing reduced the proliferation and viability of PC cells, impaired their migratory and invasive capacities, and led to their apoptosis. All these changes could be reversed by miR-942 inhibition. Further mechanical studies showed that SNHG17 silencing decreased the expression of several tumor modulators, including XXX, and this decrease was countered by miR-942 inhibition.

CONCLUSION

Our study provides experimental evidence for an interaction between SNHG17 and miR-942, which may unveil a new approach for PC pharmacotherapy.

LncRNA SNHG17 promotes the progression of oral squamous cell carcinoma by modulating miR-375/PAX6 axis

BACKGROUND

The prognosis of patients with recurrent and/or metastatic oral squamous cell carcinoma (OSCC) remains poor, and its incidence is especially high in developing countries. Multiple long non-coding RNAs (lncRNAs) are recently identified as crucial oncogenic factors or tumor suppressors. This study aimed to probe into the role of lncRNA small nucleolar RNA host gene 17 (SNHG17) on the progression of OSCC.

METHODS

The expression level of SNHG17 in OSCC samples was tested using quantitative real-time polymerase chain reaction (qRT-PCR). Human OSCC cell lines CAL-27 and Tca8113 were used in in vitro studies. Cell counting kit-8 (CCK-8) and BrdU assays were used to assess the effect of SNHG17 on OSCC cell proliferation. Flow cytometry was used to study the effect of SNHG17 on OSCC cell apoptosis. Transwell assay was conducted to detect the effect of SNHG17 on migration and invasion. Moreover, luciferase reporter assay was employed to confirm targeting relationship between miR-375 and SNHG17. Additionally, Western blot was used to observe the regulatory function of SNHG17 on PAX6.

RESULTS

SNHG17 expression in OSCC clinical samples was significantly increased and was correlated with unfavorable pathological indexes. Its overexpression remarkably accelerated proliferation and metastasis of OSCC cells, while reduced apoptosis. Accordingly, knockdown of SNHG17 suppressed the malignant phenotypes of OSCC cells. Overexpression of SNHG17 significantly reduced the expression of miR-375 by sponging it, but enhanced the expression of PAX6.

CONCLUSION

SNHG17 is a sponge of tumor suppressor miR-375 in OSCC, enhances the expression of PAX6 indirectly, and functions as an oncogenic lncRNA.

Long Non-coding RNA SNHG17 Upregulates RFX1 by Sponging miR-3180-3p and Promotes Cellular Function in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most common types of cancer that is associated with poor quality of life in patients and a global health burden. The mechanisms involved in the development and progression of HCC remain poorly understood.

Methods

Hepatocellular carcinoma human samples and cell lines were subjected to qRT-PCR for expression assessment. CCK-8 assay, Transwell migration and invasion assay, were applied for cell function detection. Animal experiment was used to measure the function of SNHG17 on cell growth in vivo. Western blot was conducted to evaluate the level of EMT in cells. RIP, RNA pull-down and luciferase reporter assays were performed to assess the correlation between SNHG17, miR-3180-3p and RFX1.

Results

Our study demonstrated that SNHG17 was upregulated in HCC human samples and involved cell proliferation, migration, invasion progress. SNHG17 promoted HCC cell growth and metastasis in vivo. Furthermore, we investigated the downstream factor of SNHG17, SNHG17 acted as a molecular sponge for miR-3180-3p, and SNHG17 regulated RFX1 expression via miR-3180-3p. SNHG17 promotes tumor-like behavior in HCC cells via miR-3180-3p/RFX1.

Conclusion

We determined RFX1 as the target of miR-3810-3p; SNHG17 enhanced the progression of HCC via the miR-3180-3p/RFX1 axis. Taken together, our findings may provide insight into the molecular mechanism involved in the progression of HCC and develop SNHG17 as a novel therapeutic target against HCC.

SNHG17 promotes the proliferation and migration of colorectal adenocarcinoma cells by modulating CXCL12-mediated angiogenesis

Background

Colorectal adenocarcinoma (CRA) is one of the leading causes of cancer-related deaths in the world. Long non-coding RNAs (lncRNAs) have been implicated to be effective regulators in the disease course of human cancers, including CRA. Small nucleolar RNA host gene 17 (SNHG17) belongs to lncRNAs, and it has been reported in breast cancer and gastric cancer. However, the function of SNHG17 and its mechanism in CRA progression remain largely unknown. In this study, we attended to shedding some light on the role of SNHG17 in CRA.

Methods

RT-qPCR was used to assess SNHG17 expression in CRA cells. CCK-8 assay, colony formation and transwell assay were carried out to detect the regulatory effect of SNHG17 silencing on CRA cell proliferation and migration. The angiogenesis of SNHG7-downregulated CRA cells was analyzed by tube formation assay. Mechanism experiments were conducted to identify the interaction between miR-23a-3p and SNHG17 or C-X-C motif chemokine ligand 12 (CXCL12).

Results

SNHG17 possessed with high expression in CRA cells. Knockdown of SNHG17 caused the inhibition on CRA cell proliferation and migration. SNHG17 promoted CRA cell proliferation and migration by sponging miR-23a-3p to upregulate CXCL12.

Conclusion

SNHG17 promotes the proliferation and migration of CRA cells by inhibiting miR-23a-3p to modulate CXCL12-mediated angiogenesis.

SNHG17 upregulates WLS expression to accelerate lung adenocarcinoma progression by sponging miR-485-5p

BACKGROUND

Long non-coding RNAs (lncRNAs) have been uncovered to be essential regulators in the biological processes of human cancers, including lung adenocarcinoma (LUAD). Recently, small nucleolar RNA host gene 17 (SNHG17) has been identified as one novel oncogenic lncRNA in gastric cancer. However, it remains unclear whether SNHG7 exert functions in LUAD progression.

METHODS

The expression levels of SNHG17, miR-485-5p and Wnt ligand secretion mediator (WLS) in LUAD cells was evaluated by RT-qPCR. The effect of SNHG7 silencing on LUAD cell proliferation was assessed by colony formation and EdU assays. The apoptosis of LUAD cells was measured by flow cytometry analysis. Transwell assays were applied to detect cell migration and invasion. The relationship between SNHG17 and miR-485-5p was validated by RIP, RNA pull down and luciferase reporter assays.

RESULTS

SNHG17 and WLS were up-regulated in LUAD cell lines. Down-regulation of SNHG17 curbed LUAD cell proliferation, migration and invasion but facilitated apoptosis. SNHG17 acted as miR-485-5p sponge to upregulate WLS expression.

CONCLUSION

SNHG17 triggers the progression of LUAD via sponging miR-485-5p to upregulate WLS expression.

lncRNA-SNHG17 promotes colon adenocarcinoma progression and serves as a sponge for miR-375 to regulate CBX3 expression

Long non-coding RNA (lncRNA) has been reported could regulate initiation and progression of colon adenocarcinoma (COAD) tumorigenesis in recent years. Small nucleolar RNA host gene 17 (SNHG17) was found play crucial roles in cancer progression but its role in COAD remains unclear. In this work, qRT-PCR was performed to detect SNHG17 expression level in COAD cell lines. Roles of SNHG17 on COAD cell behaviors were analyzed with gain and loss-of-function experiments. Luciferase activity assay, RNA pull-down assay, and RNA immunoprecipitant assay were performed to analyze the association of SNHG17 or chromobox 3 (CBX3) with microRNA-375 (miR-375). Effects of SNHG17 on miR-375/CBX3 axis were analyzed by rescue experiments. We showed SNHG17 was upregulated expression in COAD tissues and cells. Functionally, SNHG17 could promote COAD cell proliferation, colony formation, migration, and invasion in vitro. Further investigations showed SNHG17 serves as competing endogenous RNA (ceRNA) for miR-375 to regulate CBX3 expression. Additionally, we showed the roles of SNHG17 on COAD cell behaviors were exerted via miR-375/CBX3 axis. In conclusion, we demonstrated a novel SNHG17/miR-375/CBX3 triplets that participates in COAD progression, which may provide promising therapeutic targets for COAD.

SNHG17 drives malignant behaviors in astrocytoma by targeting miR-876-5p/ERLIN2 axis

Background

Astrocytoma is a common tumor type in primary central nervous system and has a high death rate around the world. Aberrant expression of long non-coding RNAs (lncRNAs) has been introduced by emerging studies to result in the development of diverse cancers.

Methods

RT-qPCR examined the expression of SNHG17, miR-876-5p and ERLIN2, and western blot evaluated ERLIN2 protein level. RNA pull down and luciferase reporter assays illustrated the relationships between SNHG17 and its downstream molecules.

Results

SNHG17 was up-regulated in astrocytoma cells. Moreover, SNHG17 silence could repress the proliferation, migration and invasion of astrocytoma cells. Besides, miR-876-5p was selected out as a downstream molecule of SNHG17 in astrocytoma. ERLIN2 was determined to be targeted by miR-876-5p. ERLIN2 mRNA and protein levels were lessened by miR-876-5p overexpression and SNHG17 silence. Additionally, miR-876-5p overexpression decelerated the biological processes of astrocytoma cells, so did ERLIN2 knockdown. More importantly, the impacts of SNHG17 down-regulation on the malignant behaviors of astrocytoma cells were counteracted by overexpressed ERLIN2 or inhibited miR-876-5p.

Conclusions

SNHG17 could induce the progression of astrocytoma by sponging miR-876-5p to elevate the expression of ERLIN2. This study indicated that SNHG17 has a high potential to be a therapeutic target for astrocytoma.

STAT3-Induced lncRNA SNHG17 Exerts Oncogenic Effects on Ovarian Cancer through Regulating CDK6

Emerging studies indicate that long noncoding RNAs (lncRNAs) play crucial roles in ovarian cancer (OC). By analyzing high-throughput data, we found that SNHG17 was highly expressed in multiple OC cohorts. However, its functions in OC were not explored. In this study, lncRNA expression in OC was analyzed by a series of microarray data. The functions of SNHG17 were investigated by various in vitro and in vivo assays. Fluorescence in situ hybridization (FISH), RNA pull-down, chromatin immunoprecipitation (ChIP), RNA immunoprecipitation (RIP), and luciferase reporter assays were used to reveal the potential mechanisms involved in the effects of SNHG17. We found that SNHG17 was overexpressed in OC and that the oncogenic transcription factor STAT3 was involved in promoting its expression. In addition, high SNHG17 expression was associated with a poor prognosis in OC. Functional analysis revealed that SNHG17 could promote OC cell growth. Mechanistically, SNHG17 was found to be located predominantly in the cytoplasm. It could regulate expression of CDK6, an important cell-cycle regulator, by acting as a molecular sponge for miR-214-3p. In summary, our study suggested that SNHG17 acted as an oncogene in OC, which might serve as a novel target for OC diagnosis and therapy.

Long non-coding RNA SNHG17 promotes proliferation, migration and invasion of glioma cells by regulating the miR-23b-3p/ZHX1 axis

BACKGROUND

Long non-coding RNA (lncRNA) small nucleolar RNA host gene 17 (SNHG17) is a carcinogenic lncRNA in diverse cancers. The expression pattern and mechanisms of SNHG17 in glioma still await verification.

METHODS

Paired glioma samples were enrolled. SNHG17, miR-23b-3p, and zinc-fingers and homeoboxes 1 (ZHX1) mRNA expression were examined by a quantitative real-time polymerase chain reaction (qRT-PCR). SNHG17 short hairpin RNA (shRNA) and miR-23b-3p mimics were transfected into LN229 and U251 cell lines to repress SNHG17 and up-regulate miR-23b-3p expression, respectively. Proliferation, migration and invasion of LN229 and U251 cells were probed by a cell counting kit-8 assay and a Transwell assay. Bioinformatics prediction, dual-luciferase reporter assay, RNA immunoprecipitation assay, qRT-PCR and western blotting were applied to determine the regulatory relationships among SNHG17, miR-23b-3p and ZHX1.

RESULTS

SNHG17 expression was markedly raised in glioma tissues, which was positively correlated with ZHX1 expression and negatively associated with the expression of miR-23b-3p. After transfection of SNHG17 shRNAs into glioma cells, the proliferation, migration and invasion of cancer cells was markedly restrained. miR-23b-3p mimics the function of SHNG17 knockdown. Furthermore, miR-23b-3p was shown to be negatively modulated by SNHG17, and ZHX1 was identified as a target of miR-23b-3p.

CONCLUSIONS

SNHG17 is a "competing endogenous RNA" with respect to modulating ZHX1 expression by adsorbing miR-23b-3p and thereby promoting glioma progression.

Long Non-coding RNA SNHG17 Promotes Cell Proliferation and Invasion in Castration-Resistant Prostate Cancer by Targeting the miR-144/CD51 Axis

Previously, we found that the expression of long non-coding RNA (lncRNA) small nucleolar RNA host gene 17 (SNHG17) was up-regulated in castration-resistant prostate cancer (CRPC) cells compared to that in hormone sensitive prostate cancer (HSPC) cells. Moreover, we found that CD51 was up-regulated in prostate cancer cells and promoted the carcinogenesis and progression of prostate cancer. However, the regulatory mechanism of SNHG17 and CD51 in the development of CRPC remains unclear. In the current study, we aimed to elucidate the expressions, functions, and underlying mechanism of SNHG17 and CD51 in CRPC. Our results further confirmed that both SNHG17 and CD51 were up-regulated in CRPC tissues and cells. In addition, we found that SNHG17 expression was positively correlated with CD51 expression in prostate cancer. Mechanically, SNHG17 functioned as a competing endogenous RNA (ceRNA) to up-regulate CD51 expression through competitively sponging microRNA-144 (miR-144), and CD51 was identified as a direct downstream target of miR-144 in CRPC. Functionally, down-regulation of SNHG17 or up-regulation of miR-144 inhibited the proliferation, migration, and invasion of CRPC cells, whereas up-regulation of SNHG17 and down-regulation of miR-144 promoted the proliferation, migration and invasion of CRPC cells in vitro and in vivo. Using gain and loss-of function assay and rescue assay, we showed that miR-144 inhibited cell proliferation, migration and invasion by directly inhibiting CD51 expression, and SNHG17 promoted cell proliferation, migration and invasion by directly enhancing CD51 expression in CRPC cells. Taken together, our study reveals the role of the SNHG17/miR-144/CD51 axis in accelerating CRPC cell proliferation and invasion, and suggests that SNHG17 may serve as a novel therapeutic target for CRPC.

SNHG17 enhances the malignant characteristics of tongue squamous cell carcinoma by acting as a competing endogenous RNA on microRNA-876 and thereby increasing specificity protein 1 expression

A long noncoding RNA called SNHG17 (small nucleolar RNA host gene 17) is aberrantly expressed and plays essential roles in multiple human cancer types. Nevertheless, its expression pattern and specific functions in tongue squamous cell carcinoma (TSCC) have not been well studied until now. Hence, in this study, we aimed to measure SNHG17 expression in TSCC and to examine the actions of SNHG17 on the malignant characteristics of TSCC cells. The regulatory mechanism that mediates the oncogenic effects of SNHG17 on TSCC cells was investigated too. In this study, SNHG17 was found to be upregulated in TSCC, and this overexpression closely correlated with adverse clinical parameters and shorter overall survival among the patients with TSCC. The SNHG17 knockdown significantly decreased TSCC cell proliferation, migration, and invasion in vitro and tumor growth in vivo. Mechanism investigation revealed that SNHG17 acts as a competing endogenous RNA on microRNA-876 (miR-876) in TSCC cells. In addition, specificity protein 1 (SP1) was validated as a direct target gene of miR-876 in TSCC cells. SP1 expression restoration in TSCC cells reversed miR-876 overexpression-induced anticancer effects. MiR-876 downregulation strongly attenuated the actions of the SNHG17 knockdown in TSCC cells. SNHG17 plays an oncogenic part in TSCC cells both in vitro and in vivo via sponging of miR-876 and thereby upregulating SP1, which could be regarded as a promising target for TSCC therapy.

Long non-coding RNASNHG17 promotes the progression of breast cancer by sponging miR-124-3p

Background

Small nucleolar RNA host gene 17 (SNHG17), a novel cancer-related long noncoding RNA (lncRNA), was reported to be responsible for processing and developing in several cancers. Nonetheless, the clinical significance and biological function of SNHG17 in human breast cancer (BC) remain rarely known.

Materials and methods

58 pairs of BC tissues and adjacent non-cancerous tissues were harvested to measure SNHG17 expression levels. SNHG17 was knockdown to study its biological behavior in BC cells. The microRNAs (miRNAs) that can bind to SNHG17 were predicated using Starbase2.0 and were tested using luciferase reporter activity and RIP assays. A xenograft model was established to investigate the impact of SNHG17 in tumor growth in vivo.

Results

An increased SNHG17 was observed in BC samples and cell lines compared with corresponding control. Increased SNHG17 was closely associated with poor prognosis.SNHG17 depletion suppressed cell proliferation, migration and invasion in vitro, as well as inhibited tumor growth in xenograft tumor models. Mechanistically, SNHG17 could function as an endogenous sponge of miR-124-3p in BC cells. Moreover, the repression of cell proliferation, migration and invasion induced by SNHG17 knockdown would reversed by miR-124-3p inhibitor.

Conclusion

The present study demonstrated that the lncRNASNHG17 could regulate the progression of BC by sponging miR-124-3p.

Long noncoding RNA SNHG17 induced by YY1 facilitates the glioma progression through targeting miR-506-3p/CTNNB1 axis to activate Wnt/β-catenin signaling pathway

Background

Glioma is one of the most widely diagnosed malignancies worldwide. It has been reported that long noncoding RNAs (lncRNAs) are participators in the tumorgenesis of cancers. Nevertheless, the role and function of lncRNA SNHG17 among glioma is unclear.

Methods

RT-qPCR revealed SNHG17, YY1, miR-506-3p, CTNNB1 expression among glioma cells. CCK-8, colony formation, EdU, flow cytometry, TUNEL and western blot assays revealed the function of SNHG17 in glioma. RIP uncovered SNHG17, miR-506-3p and CTNNB1 enrichment in RISC complex. Luciferase reporter assays and RNA pull down revealed interaction of miR-506-3p with SNHG17 and CTNNB1.

Results

SNHG17 expression was up-regulated in glioma tissues and cells. SNHG17 silence attenuated cell proliferation and promoted apoptosis and repressed tumor growth. Moreover, SNHG17 was up-regulated by transcription factor YY1. Mechanistically, SNHG17 activated Wnt/β-catenin signaling pathway in glioma. CTNNB1 was referred to as the mRNA of β-catenin, we validated that SNHG17 bound to miR-506-3p to induce CTNNB1 and activate Wnt/β-catenin signaling pathway. Rescue experiments indicated that CTNNB1 overexpression abolished the inhibitory effects of SNHG7 inhibition on glioma progression.

Conclusions

The findings that YY1-induced SNHG17 facilitated the glioma progression through targeting miR-506-3p/CTNNB1 axis to activate Wnt/β-catenin signaling pathway offered a brand-new prospects to molecular-targeted treatment for glioma.

Deregulation of long noncoding RNA SNHG17 and TTC28-AS1 is associated with type 2 diabetes mellitus

Long noncoding RNAs (lncRNAs) have emerged as key players in several biological processes and complex diseases including type 2 diabetes mellitus (T2DM). The purpose of this study was to investigate the expression levels of SNHG17 and TTC28-AS1 in T2DM patients. Quantitative real-time RT-PCR analysis was performed using peripheral blood mononuclear cells (PBMCs) samples from patients diagnosed with T2DM and healthy controls. Binary logistic regression analysis was carried out to determine the odds of development of T2DM based on expression levels of lncRNAs and clinical characteristic of the subjects. Spearman's correlation analysis was used to clarify the correlation between SNHG17 and TTC28-AS1 expressions to metabolic features. We found that SNHG17 and TTC28-AS1were down-regulated in the T2DM group compared to the healthy control group. The logistic regression revealed that body mass index (BMI), systolic blood pressure (SBP), fasting blood glucose (FBG) and TTC28-AS1 expression substantially affect T2DM susceptibility. Furthermore, expression of SNHG17 was negatively correlated with high-density lipoprotein cholesterol (HDL-C) and expression of TTC28-AS1 was positively correlated with low-density lipoprotein cholesterol (LDL-C). Decreased expressions of lncRNAs TTC28-AS1 and SNHG17 in T2DM are possibly associated with the development of T2DM.