Knockdown Induced Cell Cycle Arrest Research Articles

Down-regulation of lncRNA OGFRP1 induces autophagy and growth inhibition by AKT/mTOR signaling pathway in HCAECs.

Long noncoding RNAs (lncRNAs) have been found to play important roles in nearly all biological processes. However, the functions of the majority of LncRNAs are not fully clear. Here we evaluated the function of lncRNA OGFRP1, which has not been previously annotated, in human coronary artery endothelial cells (HCAECs). First, we knocked down lncRNA OGFRP1 in HCAECs by using siRNA transfection. qRT-PCR results indicated that siRNA1 and siRNA3 both had potent interference efficiencies. Next, by using CCK8 assay and clone formation assay, we found that siRNA3 transfection induced growth inhibition in HCAECs. Cell migration and invasion were also found to be inhibited in OGFRP1 silenced cells. Moreover, siRNA1 transfection further verified the inhibitory effects of lncRNA OGFRP1 knockdown on the proliferation, migration and invasion of HCAECs. Flow cytometry detection demonstrated that OGFRP1 knockdown induced cell cycle arrest and apoptosis. Western blot assay indicated that p70S6K and CyclinD1 were down-regulated by knockdown of OGFRP1. The intrinsic apoptosis pathway was activated in lncRNA OGFRP1 silenced cells, including increased Bax and Active-caspase 3 and decreased Bcl2. The expression of autophagy markers LC3 and Beclin1 was increased and p62 decreased, all of which indicated that cell autophagy was promoted by down-regulation of lncRNA OGFRP1. Mechanistic studies showed that lncRNA OGFRP1 inhibited the AKT/mTOR signaling pathway, including increasing phosphorylation level of AKT, mTOR and GSK3β. In conclusion, we find that down-regulation of lncRNA induces autophagy and inhibited the proliferation, migration and invasion by AKT/mTOR signaling pathway in HCAECs.

<i>ITGA2</i> Promotes Breast Cancer Stemness and Metastasis Through Enhanced <i>ACLY</i> and <i>CCND1</i> Expression

Background: Cancer metastasis is largely incurable and accounts for 90% of breast cancer deaths, especially for the aggressive basal-like or triple negative breast cancer (TNBC). Accumulating evidence demonstrates that integrins are essential for normal development and malignancies; however, the molecular functions and clinical relevance for each integrin subunit in cancer metastasis have yet to be fully elucidated. Methods: Combining patient database analyses and functional studies, we examined the association of integrin family members with clinical outcomes as well as their connection with previously identified microRNA regulators of metastasis, such as miR-206 that inhibits stemness and metastasis of TNBC. Findings: Here we report that the integrin receptor CD49b-encoding ITGA2, a direct target of miR-206, promotes breast cancer stemness and metastasis through maintaining ACLY and CCND1 levels. ITGA2 knockdown suppressed self-renewal related mammosphere formation and pluripotency marker expression, inhibited cell cycling, compromised migration and invasion, and therefore decreased lung metastasis of breast cancer. RNA sequencing analyses revealed that ITGA2 knockdown inhibits genes related to cell cycle regulation and lipid metabolism such as CCND1 and ACLY. ACLY-encoded ATP citrate lyase is essential to maintain cellular acetyl-CoA levels and mammosphere formation of breast cancer cells. Overexpression of CCND1 rescues the phenotype of ITGA2 knockdown-induced cell cycle arrest. Interpretation: We identified that the miR-206/ITGA2/ACLY/CCND1 axis is associated with relapse-free survival of the patients with high grade breast cancer, especially basal-like breast cancer, possibly serving as potential biomarkers and therapeutic targets of breast cancer stemness and metastasis. Funding Statement: This manuscript has been partially supported by NIH/NCI grants R00CA160638 (H.L. & V.A.) and R01CA213843 (R.A.K), American Cancer Society grant ACS127951-RSG-15-025-01-CSM (H.L.); the Susan G. Komen Foundation CCR15332826 (H.L.) and CCR18548501 (X.L); the Department of Defense W81XWH-16-1-0021 (H.L.); the Lynn Sage Cancer Research Foundation (X.L. and H. L.); Northwestern University's Endocrinology Training Grant T32DK007169-39 (A.H.). Declaration of Interests: There is no conflict of interest for the authors of this manuscript. Ethics Approval Statement: All animal procedures complied with the NIH Guidelines for the Care and Use of Laboratory Animals and were approved by the respective Institutional Animal Care and Use Committees.

TRRAP stimulates the tumorigenic potential of ovarian cancer stem cells

Ovarian cancer is the most fatal gynecological malignancy in women and identification of new therapeutic targets is essential for the continued development of therapy for ovarian cancer. TRRAP (transformation/transcription domain-associated protein) is an adaptor protein and a component of histone acetyltransferase complex. The present study was undertaken to investigate the roles played by TRRAP in the proliferation and tumorigenicity of ovarian cancer stem cells. TRRAP expression was found to be up-regulated in the sphere cultures of A2780 ovarian cancer cells. Knockdown of TRRAP significantly decreased cell proliferation and the number of A2780 spheroids. In addition, TRRAP knockdown induced cell cycle arrest and increased apoptotic percentages of A2780 sphere cells. Notably, the mRNA levels of stemness-associated markers, that is, OCT4, SOX2, and NANOG, were suppressed in TRRAP-silenced A2780 sphere cells. In addition, TRRAP overexpression increased the mRNA level of NANOG and the transcriptional activity of NANOG promoter in these cells. Furthermore, TRRAP knockdown significantly reduced tumor growth in a murine xenograft transplantation model. Taken together, the findings of the present study suggest that TRRAP plays an important role in the regulation of the proliferation and stemness of ovarian cancer stem cells.

Long non-coding RNA SPRY4-IT1 promotes cell proliferation and invasion by regulation of Cdc20 in pancreatic cancer cells.

Accumulating evidence has demonstrated that long non-coding RNAs (lncRNAs) play a critical role in the development of human cancers including pancreatic cancer. Long non-coding RNA SPRY4-IT1 (sprouty4-intron transcript 1) has been reported to play an oncogenic role in various types of human carcinomas. However, the role of SPRY4-IT1 in pancreatic cancer is unclear. The objective of this study was to determine the function of SPRY4-IT1 on proliferation and invasion in pancreatic cancer. In the current study, we dissected the function and mechanism of SPRY4-IT1 by multiple approaches including Real-time RT-PCR, Western blotting analysis, MTT assay, Wound healing assay, Transwell assay, and transfection. We found that down-regulation of SPRY4-IT1 inhibited cell growth and induced cell apoptosis in pancreatic cancer cells. Moreover, SPRY4-IT1 knockdown induced cell cycle arrest at G0/G1 phase. Furthermore, inhibition of SPRY4-IT1 retarded cell migration and invasion in pancreatic cancer cells. Overexpression of SPRY4-IT1 enhanced cell growth and invasion, and inhibited cell apoptosis in pancreatic cancer cells. Mechanistically, suppression of SPRY4-IT1 inhibited the expression of Cdc20 in pancreatic cancer cells. Our findings demonstrated that inhibition of SPRY4-IT1 could be a potential therapeutic approach for the treatment of pancreatic cancer.

MicroRNA miR-4779 suppresses tumor growth by inducing apoptosis and cell cycle arrest through direct targeting of PAK2 and CCND3

Depending on the function of their target genes, microRNAs (miRNAs) act as either tumor suppressors or oncogenes. Therefore, miRNAs represent a novel therapeutic strategy for prevention and management of cancer by targeting of onco-miRNAs or mimicking of tumor suppressor miRNAs. Herein, we identified novel tumor suppressor miRNAs and investigated their molecular mechanisms. To identify novel tumor suppressor miRNAs, we used 532 human miRNA mimic libraries and measured cell viability using MTS assays. The function of miR-4779 was then analyzed using cell cycle analyses and apoptosis, colony forming, and soft agar assays. Target genes of miR-4779 were predicted using TargetScan and miRDB databases and were confirmed using luciferase assays. Levels of miR-4779 and target genes in colon cancer tissue samples from patients were evaluated using qRT-PCR and western blotting analyses. Finally, in vivo tumor suppressive effects of miR-4779 were evaluated in HCT116 xenografts. In this study, miR-4779 inhibited cancer cell growth by inducing apoptosis and cell cycle arrest, and the putative survival factors PAK2 and CCND3 were identified as direct targets of miR-4779. In subsequent experiments, PAK2 knockdown induced cell cycle arrest and CCND3 knockdown induced cell cycle arrest and apoptosis. In addition, miR-4779 suppressed tumor growth and tumorigenesis in an in vivo HCT116 xenograft model. Finally, miR-4779 expression was low in 9 of 10 colon cancer tissues, whereas PAK2 and CCND3 expressions were significantly high in colon cancer tissues. The novel tumor suppressor miR-4779 inhibits cancer cell growth via cell cycle arrest and apoptosis by directly targeting PAK2 and CCND3. The present data indicate the potential of miR-4779 as a therapeutic target for miRNA-based cancer therapy.

EZH2 inhibition sensitizes tamoxifen‑resistant breast cancer cells through cell cycle regulation

Enhancer of zeste homologue 2 (EZH2), a catalytic subunit of polycomb repressive complex 2, is overexpressed in a number of different tumors including breast cancer, and serves important roles in cell cycle regulation, proliferation, apoptosis, tumorigenesis and drug resistance. However, it remains unclear whether EZH2 contributes to tamoxifen resistance in breast cancer. In the present study, the role of EZH2 in tamoxifen resistance in MCF‑7 cells was investigated. EZH2 was overexpressed in MCF‑7 tamoxifen‑resistant (MCF‑7 TamR) cells. EZH2 overexpression decreased the sensitivity of MCF‑7 cells to tamoxifen, and EZH2 knockdown improved the sensitivity of MCF‑7 TamR cells to tamoxifen. Furthermore, EZH2 knockdown induced cell cycle arrest in MCF‑7 TamR cells, accompanied by a decrease in cyclin D1 expression and an increase in p16 expression. EZH2 knockdown reduced p16 gene methylation in MCF‑7 TamR cells. These findings suggested that EZH2 overexpression may contribute to tamoxifen resistance in breast cancer, and EZH2 inhibition may reverse tamoxifen resistance in breast cancer by regulating the cell cycle via the demethylation of the p16 gene. Thus, EZH2 inhibitors may be effective for treating tamoxifen resistance in breast cancer.

Inhibition of CIP2A attenuates tumor progression by inducing cell cycle arrest and promoting cellular senescence in hepatocellular carcinoma

CIP2A is a recent identified oncogene that inhibits protein phosphatase 2A (PP2A) and stabilizes c-Myc in cancer cells. To investigate the potential oncogenic role and prognostic value of CIP2A, we comprehensively analyzed the CIP2A expression levels in pan-cancer and observed high expression level of CIP2A in majority cancer types, including hepatocellular carcinoma (HCC). Based on a validation cohort including 60 HCC and 20 non-tumorous tissue samples, we further confirmed the high mRNA and protein expression levels of CIP2A in HCC, and found high CIP2A mRNA expression level was associated with unfavorable overall and recurrence-free survival in patients with HCC. Mechanistic investigations revealed that inhibition of CIP2A significantly attenuated cellular proliferation in vitro and tumourigenicity in vivo. Bioinformatic analysis suggested that CIP2A might be involved in regulating cell cycle. Our experimental data further confirmed CIP2A knockdown induced cell cycle arrest at G1 phase. We found accumulated cellular senescence in HCC cells with CIP2A knockdown, companying expression changes of senescence associated proteins (p21, CDK2, CDK4, cyclin D1, MCM7 and FoxM1). Mechanistically, CIP2A knockdown repressed FoxM1 expression and induced FoxM1 dephosphorylation. Moreover, inhibition of PP2A by phosphatase inhibitor rescued the repression of FoxM1. Taken together, our results showed that CIP2A was highly expressed in HCC. Inhibition of CIP2A induced cell cycle arrest and promoted cellular senescence via repressing FoxM1 transcriptional activity, suggesting a potential anti-cancer target for patients with HCC.

Expression of the β3 subunit of Na+/K+-ATPase is increased in gastric cancer and regulates gastric cancer cell progression and prognosis via the PI3/AKT pathway.

ATP1B3 encodes the β3 subunit of Na+/K+-ATPase and is located in the q22-23 region of chromosome 3. Na+/K+-ATPase participates in normal cellular activities but also plays a crucial role in carcinogenesis. In the present study, we found that expression of the β3 subunit of Na+/K+-ATPase was increased in human gastric cancer tissues compared with that in normal matched tissues and that this increased expression predicted a poor outcome. ATP1B3 expression was elevated at both the mRNA and protein levels in gastric cancer cell lines relative to those in a normal gastric epithelial cell line. Interestingly, ATP1B3 knockdown significantly inhibited cell proliferation, colony-formation ability, migration, and invasion and increased apoptosis in human gastric carcinoma cell lines. Additionally, knockdown induced cell cycle arrest at the G2/M phase. Furthermore, we demonstrated that ATP1B3 silencing decreased the expression of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT) and phosphorylated AKT (p-AKT), indicating that ATP1B3 regulates gastric cancer cell progression via the PI3K/AKT signalling pathway. Hence, the β3 subunit of Na+/K+-ATPase plays an essential role in the tumourigenesis of gastric cancer and may be a potential prognostic and therapeutic target for the treatment of gastric cancer.

Downregulation of DEPTOR inhibits the proliferation, migration, and survival of osteosarcoma through PI3K/Akt/mTOR pathway.

Accumulating evidence reveals that DEP-domain containing mTOR-interacting protein (DEPTOR) plays pivotal roles in the pathogenesis and progression of many tumors. However, the expression level of DEPTOR and its function in the tumorigenesis of osteosarcoma (OS) remain unknown. In this study, we conducted quantitative real-time polymerase chain reaction, Western blot, and immunohistochemistry to detect DEPTOR expression level in human OS tissues and cell lines. To assess DEPTOR function, DEPTOR siRNA was designed and transfected into OS cells, which were then used in a series of in vitro assays. Our results indicated that DEPTOR was highly expressed in some OS tissues and cell lines. DEPTOR knockdown by siRNA dramatically inhibited cell proliferation, migration, invasion, and the formation of vasculogenic mimicry in OS cells. In addition, DEPTOR knockdown induced cell cycle arrest in the G0/G1 phase and apoptosis in the OS cell lines, MG63 and MNNG/HOS. Furthermore, we found that DEPTOR knockdown notably activated mTOR and inhibited the PI3K/Akt pathway. Taken together, these results suggest that DEPTOR overexpression is necessary for the proliferation, migration, invasion, formation of vasculogenic mimicry, and survival of OS cells and may be a potential target for the treatment of OS.

Up-regulation of CIT promotes the growth of colon cancer cells.

Colon cancer is one of the major causes of cancer mortality worldwide. However, the underlying mechanism and therapeutic targets of colon cancer have not yet been fully elucidated. In the present study, we demonstrate that citron rho-interacting, serine/threonine kinase 21 (CIT) promotes the growth of human colon cancer cells. CIT is overexpressed in human colon cancer tissues and cell lines. High expression of CIT predicts poor survival for patients with colon cancer. In colon cancer cells, CIT knockdown represses cellular proliferation and colony formation. Our in vivo xenograft experiments showed that CIT knockdown reduces the growth rate of colon cancer cells and the final tumor weight. We found that CIT knockdown induces cell cycle arrest and apoptosis in colon cancer cells. Further microarray and bioinformatics analyses indicated that CIT regulates the p53 signaling pathway, which may account for the effects of CIT on colon cancer cells. Taken together, our findings provide evidence that CIT may promote the development of colon cancer, at least in part, through the p53 signaling pathway. Therefore, CIT may be a potential therapeutic target for colon cancer treatment.

TP53 gene status is a critical determinant of phenotypes induced by ALKBH3 knockdown in non-small cell lung cancers

Human AlkB homolog 3 (ALKBH3) is overexpressed in non-small cell lung cancers (NSCLC) and its high expression is significantly correlated with poor prognosis. While ALKBH3 knockdown induces apoptosis in NSCLC cells, the underlying anti-apoptotic mechanisms of ALKBH3 in NSCLC cells remain unclear. Here we show that ALKBH3 knockdown induces cell cycle arrest or apoptosis depending on the TP53 gene status in NSCLC cells. In comparison to parental cells, TP53-knockout A549 cells showed DNA damage-responsive signal induced by ALKBH3 knockdown. TP53 knockout shifted the phenotypes of A549 cells induced by ALKBH3 knockdown from cell cycle arrest to apoptosis induction, suggesting that the TP53 gene status is a critical determinant of the phenotypes induced by ALKBH3 knockdown in NSCLC cells.

MiR-216a decreases MALAT1 expression, induces G2/M arrest and apoptosis in pancreatic cancer cells

How lncRNA MALAT1 is regulated by miRNAs at posttranscriptional level in pancreatic cancer and their regulative effects on the cancer cells remain largely unknown. By retrieving previous miRNA array data and performing primary qRT-PCR, we observed a significant negative correlation between miR-216a and MALAT1 in pancreatic ductal adenocarcinoma (PDAC) tissues and adjacent normal tissues. The following in vitro cell assay further confirmed a direct binding between miR-216a and MALAT1 and the suppressive effect of miR-216a on MALAT1 expression. MiR-216a overexpression had similar effects as MALAT1 siRNA on restoring p21 and p27 expression and inhibiting B-MYB, RAF1 and PCNA1 expression in both PANC-1 and BxPC3 cells. MiR-216a overexpression and MALAT1 knockdown induced cell cycle arrest at G2/M phase. MiR-216a overexpression not only significantly induced cell apoptosis, but also reduced cell viability and increased cell apoptosis in response to gemcitabine in the cancer cells. Based on these findings, we infer that miR-216a induces apoptosis both in the presence and absence of gemcitabine in pancreatic cancer cells by silencing MALAT1 expression.

Loss of RUNX3 expression inhibits bone invasion of oral squamous cell carcinoma.

High recurrence and lower survival rates in patients with oral squamous cell carcinoma (OSCC) are associated with its bone invasion. We identified the oncogenic role of RUNX3 during bone invasion by OSCC. Tumor growth and the generation of osteolytic lesions were significantly inhibited in mice that were subcutaneously inoculated with RUNX3-knockdown human OSCC cells. RUNX3 knockdown enhanced TGF-β-induced growth arrest and inhibited OSCC cell migration and invasion in the absence or presence of transforming growth factor-β (TGF-β), a major growth factor abundant in the bone microenvironment. RUNX3 knockdown induced cell cycle arrest at the G1 and G2 phases and promoted G2 arrest by TGF-β in Ca9.22 OSCC cells. RUNX3 knockdown also inhibited both the basal and TGF-β-induced epithelial-to-mesenchymal transition by increasing E-cadherin expression and suppressing the nuclear translocation of β-catenin. In addition, the expression and TGF-β-mediated induction of parathyroid hormone-related protein (PTHrP), one of key osteolytic factors, was blocked in RUNX3-knockdown OSCC cells. Furthermore, treating human osteoblastic cells with conditioned medium derived from RUNX3-knockdown OSCC cells reduced the receptor activator of nuclear factor-kappaB ligand (RANKL)/osteoprotegerin ratio compared with treatment with conditioned medium from RUNX3-expressing cells. These findings indicate that RUNX3 expression in OSCC cells contributes to their bone invasion and the resulting osteolysis by inducing their malignant behaviors and production of osteolytic factors. RUNX3 alone or in combination with TGF-β and PTHrP may be a useful predictive biomarker and therapeutic target for bone invasion by oral cancer.

Ubiquitin-specific protease 39 is overexpressed in human lung cancer and promotes tumor cell proliferation in vitro.

Lung cancer is the most frequent cancer in the world. Previous studies have shown that ubiquitin-specific protease 39 (USP39) is upregulated in several cancers and associated with tumor malignant characters. However, the effects of USP39 in lung cancer have not been well understood. In the present study, we found USP39 was generally expressed higher in human lung cancer tissues than in normal tissues by Oncomine database mining, qRT-PCR, and western blot assay. Knockdown of USP39 expression markedly reduced the proliferative and colony-forming ability of lung cancer cell lines 95D and A549. Flow cytometric analysis showed that USP39 knockdown induced cell cycle arrest at G2/M phase and enhanced cell apoptosis in 95D cells. Moreover, depletion of USP39 blocked activation of Akt, mTOR, p53, and PARP signaling pathways. Taken together, our study indicates that USP39 may be functionally involved in lung cancer growth and act as a potential molecular target for human lung cancer diagnosis and treatment.

HDAC10 promotes lung cancer proliferation via AKT phosphorylation.

Histone deacetylase 10 (HDAC10) is a member of the class II HDACs, and its role in cancer is emerging. In this study, we found that HDAC10 is highly expressed in lung cancer tissues. It resides mainly in the cytoplasm of lung cancer cells but resides in the nucleus of adjacent normal cells. Further examinations revealed that HDAC10 resides in the cytoplasm in multiple lung cancer cell lines, including the A549, H358 and H460 cell lines, but mainly resides in the nucleus of normal lung epithelial 16HBE cells. A leucine-rich motif, R505L506L507C508V509A510L511, was identified as its nuclear localization signal (NLS), and a mutant (Mut-505-511) featuring mutations to A at each of its original R and L positions was found to be nuclear-localization defective. Functional analysis revealed that HDAC10 promoted lung cancer cell growth and that its knockdown induced cell cycle arrest and apoptosis. Mechanistic studies showed that HDAC10 knockdown significantly decreased the phosphorylation of AKT at Ser473 and that AKT expression significantly rescued the cell cycle arrest and apoptosis elicited by HDAC10 knockdown. A co-immunoprecipitation assay suggested that HDAC10 interacts with AKT and that inhibition of HDAC10 activity decreases its interaction with and phosphorylation of AKT. Finally, we confirmed that HDAC10 promoted lung cancer proliferation in a mouse model. Our study demonstrated that HDAC10 localizes and functions in the cytoplasm of lung cancer cells, thereby underscoring its potential role in the diagnosis and treatment of lung cancer.

FKBP14 overexpression contributes to osteosarcoma carcinogenesis and indicates poor survival outcome.

The FK506-binding protein 14 (FKBP14) is a subfamily of immunophilins, has been implicated in various biochemical processes. However, its effects on the primary malignant bone tumor, osteosarcoma, are unclear. Here, we reported that FKBP14 may be an oncogene as it overexpressed in osteosarcoma tissues and cell lines, and FKBP14 expression was correlated with metastases, recurrence, tumor maximum diameter and poor survival time. FKBP14 was associated with the biological pathways including cell cycle, apoptosis and metastasis. Furthermore, we detected FKBP14 knockdown induced cell cycle arrest, apoptosis, invasion and adhesion in vitro. FKBP14 knockdown decreased the protein levels of PCNA, CDK1 and CCNB1 that promotes cell cycle, increased Bax, caspase-3 and caspase-7 protein involved in promoting cell apoptosis, and increased KIF4A expression as well as decreased SMC4 and TMEM33 proteins that contribute to cell invasion and adhesion. In addition, FKBP14 knockdown also caused a significant inhibition in tumor growth in vivo. Then, we found that the protein RhoA was identified as a binding partner of FKBP14. Taken together, FKBP14 may act as an oncogene in osteosarcoma via suppressing apoptosis and promoting invasion and adhesion in osteosarcoma carcinogenesis. FKBP14 may be a prognostic factor and potential target for osteosarcoma treatment.

Anti-tumor effect of estrogen-related receptor alpha knockdown on uterine endometrial cancer.

Estrogen-related receptor (ERR)α presents structural similarities with estrogen receptor (ER)α. However, it is an orphan receptor not binding to naturally occurring estrogens. This study was designed to investigate the role of ERRα in endometrial cancer progression. Immunohistochemistry analysis on 50 specimens from patients with endometrial cancer showed that ERRα was expressed in all examined tissues and the elevated expression levels of ERRα were associated with advanced clinical stages and serous histological type (p < 0.01 for each). ERRα knockdown with siRNA suppressed angiogenesis via VEGF and cell proliferation in vitro (p < 0.01). Cell cycle and apoptosis assays using flow cytometry and western blot revealed that ERRα knockdown induced cell cycle arrest during the mitotic phase followed by apoptosis initiated by caspase-3. Additionally, ERRα knockdown sensitized cells to paclitaxel. A significant reduction of tumor growth and angiogenesis was also observed in ERRα knockdown xenografts (p < 0.01). These findings indicate that ERRα may serve as a novel molecular target for the treatment of endometrial cancer.

ZYG11A serves as an oncogene in non-small cell lung cancer and influences CCNE1 expression.

By analyzing The Cancer Genome Atlas (TCGA) database, we identified ZYG11A as a potential oncogene. We determined the expression of ZYG11A in NSCLC tissues and explored its clinical significance. And also evaluated the effects of ZYG11A on NSCLC cell proliferation, migration, and invasion both in vitro and in vivo. Our results show that ZYG11A is hyper-expressed in NSCLC tissues compared to adjacent normal tissues, and increased expression of ZYG11A is associated with a poor prognosis (HR: 2.489, 95%CI: 1.248-4.963, p = 0.010). ZYG11A knockdown induces cell cycle arrest and inhibits proliferation, migration, and invasion of NSCLC cells. ZYG11A knockdown also results in decreased expression of CCNE1. Over-expression of CCNE1 in cells with ZYG11A knockdown restores their oncogenic activities. Our data suggest that ZYG11A may serve as a novel oncogene promoting tumorigenicity of NSCLC cells by inducing cell cycle alterations and increasing CCNE1 expression.

Downregulation of TRIM27 expression inhibits the proliferation of ovarian cancer cells in vitro and in vivo

TRIM27 (tripartite motif-containing 27) was originally identified as a fusion partner with the RET (REarranged during transfection) proto-oncogene and is highly expressed in various tumor cells and tissues. However, the level of expression and function of TRIM27 in ovarian cancer remain unclear. Here we have measured the expression of TRIM27 in normal ovarian and fallopian tube epithelial cells and in ovarian serous carcinoma cells and correlated TRIM27 expression with clinical and pathological parameters. In addition, we detected the effect of TRIM27 knockdown on proliferation of ovarian cancer cells in cell culture and xenografts. The results demonstrated that TRIM27 was highly expressed in ovarian serous carcinoma cells, and TRIM27 expression was significantly correlated with metastasis and FIGO stage in ovarian serous carcinoma patients. Downregulation of TRIM27 expression suppressed the proliferation of ovarian cancer cells in cell culture and inhibited the growth of xenografts in nude mice. TRIM27 knockdown induced cell cycle arrest and apoptosis in ovarian cancer cells by upregulating the expression of p-P38 and downregulating the expression of p-AKT. Thus the present study suggests that TRIM27 could have important roles as an oncogene during the development of ovarian cancer and could serve as a diagnostic and therapeutic target.

Upregulation of long non-coding RNA PRNCR1 in colorectal cancer promotes cell proliferation and cell cycle progression.

Colorectal cancer (CRC) is one of the most common cancers worldwide. Long non-coding RNAs (lncRNAs) have been confirmed to play a critical regulatory role in various biological processes including carcinogenesis, which indicates that lncRNAs are valuable biomarkers and therapeutic targets. The novel lncRNA prostate cancer non-coding RNA 1 (PRNCR1) is located in the susceptible genomic area of CRC, however the functional role of PRNCR1 remains unknown. Thus, we aimed to investigate the clinical significance and biological function of PRNCR1 in CRC. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to assess the expression profile of PRNCR1 in CRC tissues and cell lines. An antisense oligonucleotide (ASO) was designed to knock down PRNCR1. In a cohort of 63 patients, PRNCR1 was significantly overexpressed in CRC tissues compared with the expression in adjacent tissues, with an average fold increase of 10.55 (P=0.006). Additionally, a high level of PRNCR1 was associated with large tumor volume (P<0.05). Based on receiver operating characteristic curve (ROC), we found that the area under the curve (AUC) of PRNCR1 was 0.799 while the AUC of conventional biomarker CEA-CA199 was 0.651, indicating that PRNCR1 could be a sensitive diagnostic biomarker of CRC. Compared with the normal human colorectal epithelial cell line (FHC), PRNCR1 was upregulated in most CRC cell lines (HCT116, SW480, LoVo and HT-29). After knockdown of PRNCR1 by ASO, CRC cell proliferation ability was significantly inhibited. We further found that PRNCR1 knockdown induced cell cycle arrest in the G0/G1 phase and a significant decrease in the proportion of cells in the S phases. In contrast, PRNCR1 knockdown did not affect cell apoptosis or invasive ability. Hence, these data indicate that PRNCR1 promotes the proliferation of CRC cells and is a potential oncogene of CRC.