RhoC Expression Research Articles

Elevated expression of wildtype RhoC promotes ErbB2- and Pik3ca-induced mammary tumor formation

Copy number gains in genes coding for Rho activating exchange factors as well as losses affecting genes coding for RhoGAP proteins are common in breast cancer (BC), suggesting that elevated Rho signaling may play an important role. Extra copies and overexpression of RHOC also occur, although a role for RhoC overexpression in driving tumor formation has not been assessed in vivo. To this end, we report on the development of a Rosa26 (R26)-targeted Cre-conditional RhoC overexpression mouse (R26RhoC). This mouse was crossed to two models for ERBB2/NEU+ breast cancer: one based on expression of an oncogenic ErbB2/Neu cDNA downstream of the endogenous ErbB2 promoter (FloxNeoNeuNT), the other, a metastatic model that is based on high-level expression from MMTV regulatory elements (NIC). RhoC overexpression dramatically enhanced mammary tumor formation in FloxNeoNeuNT mice but showed a more subtle effect in the NIC line, which forms multiple mammary tumors after a very short latency. RhoC overexpression also enhanced mammary tumor formation in an activated Pik3ca model for breast cancer (Pik3caH1047R). The transforming effect of RhoC was associated with epithelial/mesenchymal transition (EMT) in ErbB2/NeuNT and Pik3caH1047R systems. Thus, our study reveals the importance of elevated wildtype Rho protein expression as a driver of breast tumor formation and highlights the significance of Copy Number Abberations that affect Rho signalling.

Abstract 5449: Exploring signaling pathways essential for stemness and metastasis of colorectal cancer cells

Abstract The prognosis of colorectal cancer (CRC) patients with distant metastasis remains poor, requiring elucidation of molecular mechanisms and identification of therapeutic targets. While cancer stem cells have been implicated in metastasis, recurrence, and drug resistance, our understanding of the regulatory mechanisms governing the stemness of CRC stem cells remains largely incomplete. In this study, we utilized an innovative autochthonous metastatic mouse model of CRCs generated by the introduction of sporadic mutations in Ctnnb1, Kras, Trp53, and Smad4 genes (CKPS mice) and CRC cell lines derived from the mice (CKPS cells). Our investigation revealed that the cAMP/PKA/CREB and TGFβ/SMAD4 pathways play a positive and negative role, respectively, in the sphere-forming and metastasis-initiating ability of CRC cells. Treatment with the CREB inhibitor 666-15 or the genetic knockout of CREB significantly reduced the spheroid-forming and metastasis-initiating potentials of CKPS cells. Intriguingly, we observed that the irinotecan treatment induced CREB phosphorylation in liver metastases, and co-treatment of 666-15 greatly potentiated the inhibitory effect of irinotecan on liver metastasis. Furthermore, we found that the transition from 2D to 3D spheroid culture of CKPS cells led to the induction of RhoC expression. Notably, RhoC knockout in CKPS cells effectively suppressed spheroid formation in vitro and inhibited metastasis formation in an intrasplenic injection liver metastasis assay. Potential therapeutic implications of these findings will be discussed. Citation Format: Teruaki Fujishita, Makoto M. Taketo, Masahiro Aoki. Exploring signaling pathways essential for stemness and metastasis of colorectal cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5449.

ARHGAP29 Is Involved in Increased Invasiveness of Tamoxifen-resistant Breast Cancer Cells and its Expression Levels Correlate With Clinical Tumor Parameters of Breast Cancer Patients.

Aggressive breast cancer (BC) cells show high expression of Rho GTPase activating protein 29 (ARHGAP29), a negative regulator of RhoA. In breast cancer cells in which mesenchymal transformation was induced, ARHGAP29 was the only one of 32 GTPase-activating enzymes whose expression increased significantly. Therefore, we investigated whether there is a correlation between expression of ARHGAP29 and tumor progression in BC. Since tamoxifen-resistant BC cells exhibit increased mesenchymal properties and invasiveness, we additionally investigated the relationship between ARHGAP29 and increased invasion rate in tamoxifen resistance. The question arises as to whether ARHGAP29 is a suitable prognostic marker for the progression of BC. Tissue microarrays were used to investigate expression of ARHGAP29 in BC and adjacent normal breast tissues. Knockdown experiments using siRNA were performed to investigate the influence of ARHGAP29 and the possible downstream actors RhoC and pAKT1 on invasive growth of tamoxifen-resistant BC spheroids in vitro. Expression of ARHGAP29 was frequently increased in BC tissues compared to adjacent normal breast tissues. In addition, there was evidence of a correlation between high ARHGAP29 expression and advanced clinical tumor stage. Tamoxifen-resistant BC cells show a significantly higher expression of ARHGAP29 compared to their parental wild-type cells. After knockdown of ARHGAP29 in tamoxifen-resistant BC cells, expression of RhoC was significantly reduced. Further, expression of pAKT1 decreased significantly. Invasive growth of three-dimensional tamoxifen-resistant BC spheroids was reduced after knockdown of ARHGAP29. This could be partially reversed by AKT1 activator SC79. Expression of ARHGAP29 correlates with the clinical tumor parameters of BC patients. In addition, ARHGAP29 is involved in increased invasiveness of tamoxifen-resistant BC cells. ARHGAP29 alone or in combination with its downstream partners RhoC and pAKT1 could be suitable prognostic markers for BC progression.

Trametenolic acid inhibits migration and invasion of hepatocellular carcinoma HepG2.2.15 cells via RhoC/ROCK1 pathway

This study investigated the effect of trametenolic acid(TA) on the migration and invasion of human hepatocellular carcinoma HepG2.2.15 cells by using Ras homolog gene family member C(RhoC) as the target and probed into the mechanism, aiming to provide a basis for the utilization of TA. The methyl thiazolyl tetrazolium(MTT) assay was employed to examine the proliferation of HepG2.2.15 cells exposed to TA, and scratch and Transwell assays to examine the cell migration and invasion. The pull down assay was employed to determine the impact of TA on RhoC GTPase activity. Western blot was employed to measure the effect of TA on the transport of RhoC from cytoplasm to cell membrane and the expression of RhoC/Rho-associated kinase 1(ROCK1)/myosin light chain(MLC)/matrix metalloprotease 2(MMP2)/MMP9 pathway-related proteins. RhoC was over-expressed by transient transfection of pcDNA3.1-RhoC. The changes of F-actin in the cytoskeleton were detected by Laser confocal microscopy. In addition, the changes of cell migration and invasion, expression of proteins in the RhoC/ROCK1/MLC/MMP2/MMP9 pathway, and RhoC GTPase activity were detected. The subcutaneously transplanted tumor model of BALB/c nude mice and the low-, medium-, and high-dose(40, 80, and 120 mg·kg~(-1), respectively) TA groups were established and sorafenib(20 mg·kg~(-1)) was used as the positive control. The tumor volume and weight in each group were measured, and the expression of related proteins in the tumor tissue was determined by Western blot. The results showed that TA inhibited the proliferation of HepG2.2.15 cells in a concentration-dependent manner, with the IC_(50) of 66.65 and 23.09 μmol·L~(-1) at the time points of 24 and 48 h, respectively. The drug administration groups had small tumors with low mass. The tumor inhibition rates of sorafenib and low-, medium-and high-dose TA were 62.23%, 26.48%, 55.45%, and 62.36%, respectively. TA reduced migrating and invading cells and inhibited RhoC protein expression and RhoC GTPase activity in a concentration-dependent manner, dramatically reducing RhoC and membrane-bound RhoC GTPase. The expression of ROCK1, MLC, p-MLC, MMP2, and MMP9 downstream of RhoC can be significantly inhibited by TA, as confirmed in both in vitro and in vivo experiments. After HepG2.2.15 cells were transfected with pcDNA3.1-RhoC to overexpress RhoC, TA down-regulated the protein levels of RhoC, ROCK1, MLC, p-MLC, MMP2, and MMP9 and decreased the activity of RhoC GTPase, with the inhibition level comparable to that before overexpression. In summary, TA can inhibit the migration and invasion of HepG2.2.15 cells. It can inhibit the RhoC/ROCK1/MLC/MMP2/MMP9 signaling pathway by suppressing RhoC GTPase activity and down-regulating RhoC expression. This study provides a new idea for the development of autophagy modulators targeting HSP90α to block the proliferation and inhibit the invasion and migration of hepatocellular carcinoma cells via multiple targets of active components in traditional Chinese medicines.

ECM1 promotes migration and invasion in endometriosis

Extracellular matrix protein 1 (ECM1) is a glycoprotein that may be a key player in tumorigenesis and tumor progression. However, knowledge regarding the role of ECM1 in endometriosis (EM) is still lacking. Microarray analyses were performed to compare the mRNA expression patterns between paired EU tissues and ectopic endometrial (EC) tissues (n = 4) from EM patients. ECM1 expression was significantly increased in the eutopic endometrial (EU) tissues than paired EC tissues of endometriotic patients and normal endometrial (NE) tissues of controls without EM. Blocking ECM1 with siRNA attenuated the migration and invasion of hEM15A cells and modified the distribution of the F-actin cytoskeleton. We conducted microarray analyses and bioinformatics analyses to investigate the differentially expressed genes (DEGs) and related pathways regulated by ECM1. A total of 161 DEGs between the siECM1 and the negative control (siNC) treatments were identified, consisting of 79 downregulated genes and 82 upregulated genes. Enriched DEGs were associated with 9 gene ontology (GO) terms. Moreover, a protein-protein interaction (PPI) network was constructed for the hub genes and modules. Radixin (RDX) was the second most downregulated gene in the siECM1 group compared with the siNC group. ECM1 knockdown significantly decreased the expression of RDX, RhoC, ROCK1, N-cadherin and β-catenin but not ROCK2. ECM1 showed high tissue-specific expression in EU tissues from EM patients, and may contribute to the migration, invasion and reorganization of the F-actin cytoskeleton in eutopic endometrial stromal cells via the RhoC/ROCK1 signaling pathway in EM.

Clinical implications of RAB13 expression in pan-cancer based on multi-databases integrative analysis

Worldwide, cancer is a huge burden, and each year sees an increase in its incidence. RAB (Ras-related in brain) 13 is crucial for a number of tumor types. But more research on RAB13's tumor-related mechanism is still required. This study's goal was to investigate RAB13's function in human pan-cancer, and we have also preliminarily explored the relevant mechanisms. To investigate the differential expression, survival prognosis, immunological checkpoints, and pathological stage of RAB13 in human pan-cancer, respectively, databases of TIMER2.0, GEPIA 2, and UALCAN were employed. CBioPortal database was used to analyze the mutation level, meanwhile, PPI network was constructed based on STRING website. The putative functions of RAB13 in immunological infiltration were investigated using single sample gene set enrichment analysis (ssGSEA). The mechanism of RAB13 in hepatocellular cancer was also briefly investigated by us using gene set enrichment analysis (GSEA). RAB13 was differentially expressed in a number of different cancers, including liver hepatocellular carcinoma (LIHC), stomach adenocarcinoma (STAD), etc. Additionally, RAB13 overexpression in LGG and LIHC is associated with a worse prognosis, including overall survival (OS) and disease-free survival (DFS). Then, we observed that early in BLCA, BRAC, CHOL, ESCA, HNSC, KICH, KIRC, LIHC, LUAD, LUSC, and STAD, the level of RAB13 expression was raised. Next, we found that “amplification” was the most common mutation in RAB13. The expression of SLC39A1, JTB, SSR2, SNAPIN, and RHOC was strongly positively linked with RAB13, according to a correlation study. RAB13 favorably regulated B cell, CD8 + T cell, CD4 + T cell, macrophage, neutrophil, and dendritic cell in LIHC, according to immune infiltration analysis. Immune checkpoint study revealed a positive correlation between RAB13 expression and PD1, PDL1, and CTLA4 in LIHC. According to GSEA, RAB13 is involved in a number of processes in LIHC, including MTORC1 signaling, MYC targets v1, G2M checkpoint, MITOTIC spindle, DNA repair, P53 pathway, glycolysis, PI3K-AKT-MTOR signaling, etc. RAB13 is a possible therapeutic target in LIHC and can be used as a prognostic marker.

Colonoscopy Combined with Me-Nbi to Observe the Canceration Characteristics of Colon Polyps and the Correlation of RHOC Protein Expression.

The current study was carried out to analyze the characteristics of colon polyps canceration observed by colonoscopy combined with ME-NBI (Magnifying Endoscopy combined with Narrow-Band Imaging) and its correlation with RhoC (Ras homolog gene family, member C) protein expression. For this purpose, A total of 300 patients with colorectal polyps and cancerous lesions (192 colorectal polyps and 200 cancerous lesions) who were treated in the digestive endoscopy room of the hospital and underwent colonoscopy were selected, and they were divided into polyp group and malignant lesion according to the diagnosis results. groups, 150 cases in each group. There were 75 patients with non-adenomatous polyps and 75 patients with adenomatous polyps in the polyp group; 75 patients with high-grade neoplasia and cancerous changes in the malignant group. The microvascular structure and surface structure of the lesions were observed by colonoscopy, and the correlation between microvascular morphological characteristics and RhoC protein expression was analyzed. Results showed that the probability of positive RhoC protein expression in the polyp group was significantly lower than that in the malignant transformation group, and the difference was statistically significant (P<0.05). In the malignant transformation group, the positive rate of RhoC expression in mucosal and submucosal superficial infiltration of 150 patients with colon polyp carcinoma was lower than that in submucosal deep infiltration, and the difference was statistically significant (P<0.05). NICE (National Institute for Clinical Excellence) type 2 was diagnosed as colorectal superficial submucosal The sensitivity, specificity, and accuracy of colorectal submucosal invasion were 73.1%, 84.6%, and 83.2%, respectively; the sensitivity, specificity, and accuracy of NICE type 3 in diagnosing colorectal submucosal invasion were 74.6%, 96.8%, and 92.7%, respectively. . Type 2 and type 3 lesions with cancerous features in NICE classification were correlated with the expression of RhoC protein (P<0.05). In conclusion, NICE classification under colonoscopy combined with magnifying colonoscopy has a good effect on colorectal lesions. Differential diagnostic value, RhoC protein is highly expressed in colon cancer and is closely related to the occurrence of colon cancer and the depth of lesion invasion. With the progression of colorectal adenomas, the expression of RhoC protein in the lesions gradually increased.

Proteomic Analysis of Mesenchymal Stem Cells and Monocyte Co-Cultures Exposed to a Bioactive Silica-Based Sol-Gel Coating.

New methodologies capable of extensively analyzing the cell-material interactions are necessary to improve current in vitro characterization methods, and proteomics is a viable alternative. Also, many studies are focused on monocultures, even though co-cultures model better the natural tissue. For instance, human mesenchymal stem cells (MSCs) modulate immune responses and promote bone repair through interaction with other cell types. Here, label-free liquid chromatography tandem mass spectroscopy proteomic methods were applied for the first time to characterize HUCPV (MSC) and CD14+ monocytes co-cultures exposed to a bioactive sol-gel coating (MT). PANTHER, DAVID, and STRING were employed for data integration. Fluorescence microscopy, enzyme-linked immunosorbent assay, and ALP activity were measured for further characterization. Regarding the HUCPV response, MT mainly affected cell adhesion by decreasing integrins, RHOC, and CAD13 expression. In contrast, MT augmented CD14+ cell areas and integrins, Rho family GTPases, actins, myosins, and 14-3-3 expression. Also, anti-inflammatory (APOE, LEG9, LEG3, and LEG1) and antioxidant (peroxiredoxins, GSTO1, GPX1, GSHR, CATA, and SODM) proteins were overexpressed. On co-cultures, collagens (CO5A1, CO3A1, CO6A1, CO6A2, CO1A2, CO1A1, and CO6A3), cell adhesion, and pro-inflammatory proteins were downregulated. Thus, cell adhesion appears to be mainly regulated by the material, while inflammation is impacted by both cellular cross-talk and the material. Altogether, we conclude that applied proteomic approaches show its potential in biomaterial characterization, even in complex systems.

Investigating the prognosis gene profile of triple-negative breast cancer

Background: Current therapeutic strategies have poor effects in triple-negative breast cancer (TNBC) patients due to lack of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2 expression. Identification of novel genes of TNBC prognosis aids in the development of effective treatment strategies. Aim: We aim at explore key genes related to TNBC recurrence. Methods: RNAseq and clinical characteristics data were derived from The Cancer Genome Atlas Breast Invasive Carcinoma project. Ninety-seven TNBC patients were included. We used DESeq2 and Cox regression to identify significant genes to TNBC recurrence. Pathway enrichment analysis and protein–protein interaction plot were conducted to understand the functions of target genes. Results: We discovered top nine important genes for TNBC recurrence. Lower mRNA expression of potassium voltage-gated channel subfamily Q member 5, H3 clustered histone 10, and ADP-ribosylation factor-like protein 17 and higher mRNA expression of synuclein beta, interleukin 6 (IL-6), casein kappa, RHOC, phosphodiesterase 8B, and laminin subunit alpha 3 (LAMA3) were associated with higher risk of recurrence. IL-6, LAMA3, and Ras homolog family member V (RHOV) genes out of nine candidate genes can make the best prediction of TNBC recurrence (area under receiver operating characteristic curve: 0.95, sensitivity: 0.89 and specificity: 0.97). The top three significant Gene Ontology (GO) pathways are nucleosome, ion gated channel activity, and epidermis development. Significant GO pathways can be categorized into four functions: cell–cell adhesion, cell transportation, cell proliferation, ion channel and transporter, and immune. Conclusion: We discovered that the gene set of IL6, LAMA3, and RHOV can accurately predict TNBC recurrence. These genes warrant further study to confirm their causal association with TNBC prognosis and possible treatment targets.

Silencing of RhoC induces macrophage M1 polarization to inhibit migration and invasion in colon cancer via regulating the PTEN/FOXO1 pathway.

Ras homologue family member C (RhoC) is an oncogene in diverse types of human cancers, whereas its regulatory mechanisms involving macrophage polarization is rarely investigated. This study is designed to explore the regulatory role of RhoC in colon cancer and the underlying molecular mechanisms involving macrophage polarization. We detected RhoC expression by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot, and analysed the biological function of RhoC knockdown in CC cells by the MTT, wound healing and transwell assay. Macrophage polarization-associated markers, genes associated with migration, phosphatase and tensin homologue (PTEN) and forkhead box O (FOXO) were determined by qRT-PCR and western blot. The xenograft tumour mouse model was used to assess the role of RhoC in vivo. RhoC is highly expressed in CC cells. The cell viability, invasion and migration abilities of CC cells were reduced by knockdown of RhoC. RhoC knockdown promoted M1 polarization, inhibited M2 polarization and decreased levels of genes associated with migration (matrix metalloproteinase-2 and matrix metalloproteinase-9). Silencing of RhoC inhibited tumour growth and expression of genes associated with migration in the xenografted model. In addition, silencing of RhoC promoted PTEN/FOXO1 expression, and PTEN inhibitor (SF1670) reversed the inhibitory effects of RhoC silencing. We demonstrated that silencing of RhoC reduced CC cells invasion and migration, and tumour growth by suppressing M2 macrophage polarization via regulating the PTEN/FOXO1 pathway.

Expression of epithelial–mesenchymal transition markers in squamous cell carcinoma of the uterine cervix: A cross-sectional study

Background: Cervical cancer is the fourth most common cancer in women worldwide. Epithelial– mesenchymal transition (EMT) is a phenomenon related to carcinogenesis, which is characterized by morphological changes from neoplastic epithelial cells to mesenchymal cells, resulting in increased motility and invasiveness of neoplastic cells. To observe the expression of three EMT markers (cytokeratin 19 [CK1]), vimentin, and Ras homolog gene family member C [RhoC]) in individuals with a normal cervix, patients with high-grade squamous intraepithelial lesion (HSIL), and patients with squamous cell carcinoma (SCC) and determine the association with the histological grade and clinical/radiological stage of cervical cancer. Methods: Seventy participants were included in the study: 10 individuals with a normal cervix, 30 patients with HSIL, and 30 patients with newly diagnosed SCC. Immunohistochemistry for CK19, vimentin, and RhoC was performed in all groups. The association of the expressions of the three markers between the groups was analyzed. P values of &lt; 0.005 were considered statistically significant. Results: The mean age of the normal cervix, HSIL, and SCC groups was 46.2 ± 16.12, 49.10 ± 10.13, and 56.27 ± 9.29 years, respectively. CK19 showed a weak basal cell positivity in 80% of the individuals with a normal cervix. Meanwhile, 93.3% and 100% of the patients with HSIL and SCC, respectively, were positive for CK19; the association of the expressions between the groups was insignificant. Vimentin was negative in the normal cervix group and positive in the HSIL (33.3%) and SCC (73.3%) groups; the association of the expressions between the groups was significant. RhoC was positive in the normal cervix, HSIL, and SCC groups (10%, 20%, and 83.33%, respectively), and the association of the expressions between them was significant. There was no significant association found between the expression of vimentin or RhoC and the histopathological grade or FIGO stage. Conclusion: An increased expression of CK19 in patients with HSIL and SCC of the cervix highlights the role of basal cells in cervical carcinogenesis. The expression of vimentin and RhoC in individuals with a normal cervix and patients with HSIL and SCC indicates EMT.

Chemoprevention of 4NQO-Induced Mouse Tongue Carcinogenesis by AKT Inhibitor through the MMP-9/RhoC Signaling Pathway and Autophagy.

Oral cancer (OC), the most common cancer in the head and neck, which has a poor prognosis, histopathologically follows a stepwise pattern of hyperplasia, dysplasia, and cancer. Blocking the progression of OC in the precancer stage could greatly improve the survival and cure rates. AKT protein plays a critical role in the signal transduction of cancer cells, and we found that AKT was overexpressed in human OC samples through analysis of TCGA database. Therefore, this study is aimed at investigating the chemopreventive effect of an AKT inhibitor (MK2206 2HCl) on OC. In vivo, we established a 4-nitroquinoline-1-oxide- (4NQO-) induced mouse tongue carcinogenesis model to investigate the potential chemopreventive effect of MK2206 2HCl on mouse OC resulting from 4NQO. The results showed that MK2206 2HCl could significantly reduce the incidence rate and growth of OC, inhibit the transformation of dysplasia to cancer in the 4NQO-induced mouse tongue carcinogenesis model, and simultaneously markedly suppress cell proliferation, angiogenesis, and mast cell (MC) infiltration in 4NQO-induced mouse tongue cancers. In vitro, our results revealed that MK2206 2HCl could also inhibit oral squamous cell carcinoma (OSCC) cell malignant biological behaviors, including cell proliferation, colony formation, cell invasion, and migration, while promoting apoptosis. Mechanistic studies revealed that MK2206 2HCl suppressed matrix metalloproteinase 9 (MMP-9) and RhoC expression and promoted autophagy gene LC3 II expression. In summary, our findings demonstrated the chemopreventive effect of MK2206 2HCl on the 4NQO-induced mouse tongue carcinogenesis model, which likely has an underlying mechanism mediated by the MMP-9/RhoC signaling pathway and autophagy.

LACTB suppresses migration and invasion of glioblastoma via downregulating RHOC/Cofilin signaling pathway

Glioblastoma (GBM) is the most malignant tumor in human brain. High invasiveness of this tumor is the main reason causing treatment failure and recurrence. Previous study has found that LACTB is a novel tumor suppressor in breast cancer. Moreover, the function of LACTB in other tumors and mechanisms involving LACTB were also reported. However, the role and relevant mechanisms of LACTB in GBM invasion remains to be revealed. Our aim is to investigate the role LACTB in GBM migration and invasion. We found that LACTB was downregulated in gliomas compared to normal brain tissues. Overexpression of LACTB suppressed migration and invasion of LN229 and U87 cell lines. Mechanistically, LACTB overexpression downregulated the mesenchymal markers. Moreover, LACTB overexpression downregulated the expression of RHOC and inhibited RHOC/Cofilin signaling pathway. The study suggests that LACTB suppresses migration and invasion of GBM cell lines via downregulating RHOC/Cofilin signaling pathway. These findings suggest that LACTB may be a potential treatment target of GBM.

RNF168 suppresses the cancer stem cell-like traits of nonsmall cell lung cancer cells by mediating RhoC ubiquitination.

The critical roles of E3 ubiquitin ligase RNF168 have been widely revealed in various tumors, however, its roles in lung cancer progression are still confusing. Here, we found that RNF168 expression is positively correlated with the overall survival, first-progression survival, and postprogression survival of lung adenocarcinoma, but not correlated with these survivals of squamous cell carcinoma of lung. Furthermore, it was shown that RNF168 mRNA expression is lowly expressed in lung adenocarcinoma tissues, but highly expressed in squamous cell carcinoma of lung. Functional experiments indicated that RNF168 overexpression significantly suppressed the cancer stem cell (CSC)-like traits of nonsmall cell lung cancer (NSCLC) cells, as characterized by the attenuation of sphere-formation ability, ALDH activity, and the expression of lung CSC markers. Mechanistic studies demonstrated that RNF168 facilitated the ubiquitination of RhoC, which had been considered as a fascinating target for CSCs, and thus promoted RhoC protein degradation. Notably, RNF168 failed to affect the mRNA expression of RhoC and overexpression of RhoC rescued the inhibitory effects of RNF168 overexpression on the CSC-like traits of NSCLC cells. Therefore, this study revealed RNF168 as a novel regulator of RhoC protein in NSCLC cells, this RNF168/RhoC regulatory axis might be a potential target for NSCLC treatment.

RHOC EXPRESSION CORRELATES WITH SRC AND IT IS A PROGNOSTIC FACTOR IN ACUTE MYELOID LEUKEMIA

Acute Myeloid Leukemia (AML) is a hematologic malignancy with poor prognosis that can occur from myelodysplastic syndrome (MDS) progression. RHOC is a Rho GTPase protein involved in cancer progression, but its expression and function have not been explored in these diseases. To investigate the expression and signaling pathways related to RHOC in AML and MDS. RHOC gene expression was analyzed by quantitative PCR in bone marrow samples from patients with MDS (n = 47) or AML (n = 58), and heathy donors (n = 14), attended at University of Campinas. The study was approved by the local Ethical Committee on Human Research. Clinical and genomic data of AML patients from The Cancer Genome Atlas (TCGA, n = 173) were also analyzed. Risk factors impacting overall survival (OS) and disease-free survival (DFS) were estimated using a Cox regression model. SRC expression was evaluated by western blot in U937 leukemia cell line stably silenced for RHOC using lentiviral vector-mediated shRNA. RHOC expression was increased in AML patients with previous MDS (n = 15) and de novo AML (n = 43), compared to normal hematopoietic cells (all p < 0.05). No significant differences in RHOC expression were observed in MDS patients. Bone marrow samples from four MDS patients of our cohort were analyzed before and after progression to AML. Interestingly, these patients presented increased RHOC expression after the progression. Analysis from TCGA study revealed that RHOC was upregulated in patients with adverse cytogenetic risk compared to AML with intermediate cytogenetic risk. Univariate analysis showed that higher levels of RHOC (above median) impacted OS and DFS (all p < 0.05). Multivariate analysis confirmed that higher RHOC was an independent prognostic factor for inferior OS (HR = 1.378, CI= 1.194-1.699, p < 0.001) and DFS (HR = 1.421, CI=1.086-1.860, p < 0.010). Higher RHOC expression was associated with the presence of TP53 mutations, and lower RHOC was associated with the presence of CEBPA or NPM1 or WT1 mutations (Fisher's exact test). Gene set enrichment analysis revealed that RHOC is associated with signaling pathways such as regulation of actin cytoskeleton, apoptosis, and DNA damage responses. In addition, RHOC expression positively correlated with the expression of SRC oncogene (R = 0,61, Spearman; p = 4,63e-19). Notably, leukemia cells silenced for RHOC presented decreased SRC protein expression. RHOC expression is increased in AML and negatively impacts patient survival. These results may be possibly explained by the RHOC relation with SRC and participation in signaling pathways such as migration, apoptosis, and DNA damage responses. Funding: FAPESP, and CAPES.

Retraction Note to: Lupeol inhibits migration and invasion of colorectal cancer cells by suppressing RhoA-ROCK1 signaling pathway.

Metastasis is the main cause of death in colorectal cancer (CRC) patients. However, current treatment options for CRC metastasis are very limited. Lupeol, a triterpene that is widely found in vegetables and fruits, has been reported to possess the cancer-preventive and anti-inflammatory functions. However, the roles of Lupeol in the migration and invasion of colorectal cancer remain unclear. Here, we evaluated the effect of Lupeol treatment on colorectal cancer cell lines, HCT116 and SW620, and delineated its underlying mechanisms. Our results showed that Lupeol induced a dose-dependent inhibition of HCT116 and SW620 cells viability, measured by CCK8 assay. Wound healing and Transwell migration and invasion assays revealed that Lupeol significantly suppressed the migration and invasion of CRC cells. Using laser confocal microscope, we observed that the pseudopods and protrusions of HCT116 and SW620 cells decreased and disrupted after treatment with Lupeol. In addition, the quantitative real-time PCR and Western blotting results showed that Lupeol downregulated the expression of RhoA and RhoC, and their downstream effectors ROCK1, Cofilin, p-MLC, and the associated regulatory protein Cyclin A2. Interestingly, the migration and invasion capacity of CRC cells was reduced after RhoA knockdown. And there were no additional changes in CRC cells with RhoA knockdown to treat with Lupeol. These findings demonstrate that Lupeol can suppress the migration and invasion of colorectal cancer cells by remodeling the actin cytoskeleton via RhoA-ROCK1 pathway inhibition, which may provide an effective anti-metastatic agent for CRC patients.

The association of transcription factor Prox1 with the proliferation, migration, and invasion of lung cancer

BackgroundThe current study investigates the effect of transcription factor Prox1 on the proliferation, migration, and invasion ability of lung cancer.MethodsLung cancer cell lines (A549 and H446 cells) were transfected with Prox1NAD and siRNA, respectively. Thus, the A549 and H446 cells overexpressed Prox1 after transfection of Prox1NAD plasmids, and A549 and H446 cells have low expression of Prox1 after transfection with siRNA. Reverse transcriptase quantitative PCR and western blot analyses were used to detect Prox1 mRNA and protein expression in cells. Plate clone formation experiments and MTT experiments were used to detect cell proliferation. Western blot was used to detect the expression of Rho family-related proteins in cells.ResultsCompared to untransfected wild-type A549 and H446 that served as blank controls, the expression level of Prox1mRNA and protein in A549 and H446 cells overexpressing Prox1 after plasmid transfection was high, while the expression level of Prox1mRNA and protein in A549 and H446 cells with low expression of Prox1 after siRNA transfection was low. With the increase of Prox1 expression, the expression of RhoA and RhoC increased, while the expression of RhoB decreased.ConclusionThe finding of this study may provide a new approach for the treatment of lung cancer using targeted gene therapy.

MMP-9 Knockdown Inhibits Oral Squamous Cell Carcinoma Lymph Node Metastasis in the Nude Mouse Tongue-Xenografted Model through the RhoC/Src Pathway.

Oral squamous cell carcinoma (OSCC) is one of the most common types of cancers in developing countries. A major contributor to the high mortality rate of OSCC is the tendency of oral cancer cells to metastasize to lymph nodes around the head and neck during the early stages of cancer development. Matrix metalloproteinase 9 (MMP-9), an endopeptidase, can degrade the extracellular matrix and basement membrane and plays a key role in tumor invasion and metastasis. In vitro, cell migration ability was conducted by scratching assays. We also investigated the interaction abilities between OSCC cells and vascular endothelial cells (ECs) by an adhesion assay and transendothelial migration assay. And we established a BALB/c nude mouse tongue-xenografted metastasis model to investigate the role of MMP-9 and explore its potential underlying mechanism in OSCC growth, lymph node metastasis, and angiogenesis in vivo. The results showed that knockdown of MMP-9 could significantly suppress OSCC cell migration, proliferation, interactions between endothelial cells, xenografted tumor growth, and angiogenesis and simultaneously markedly inhibited OSCC cell metastasis to mouse lymphonodi cervicales superficiales, axillary lymph nodes, and even distant inguinal lymph nodes. Mechanistic studies revealed that knockdown of MMP-9 also led to a decreased expression of RhoC, Src, and F-actin by RT-PCR, western blotting, and immunohistochemistry. And the bioinformatic analysis showed that MMP-9, RhoC, and Src mRNA expression was positively and linearly correlated in OSCC on TCGA database. Together, our findings indicated that MMP-9 plays a very important role in OSCC growth, migration, angiogenesis, and lymph node metastasis, and its potential mechanism may be mediated by RhoC and Src gene expression.

Circular RNA AKT3 governs malignant behaviors of esophageal cancer cells by sponging miR-17-5p.

BACKGROUNDRecent studies have demonstrated that circular RNA AKT3 (circAKT3) plays a crucial role in regulating the malignant phenotypes of tumor cells. However, the potential effects of circAKT3 on esophageal cancer have not been investigated.AIMTo illuminate the role of circAKT3 in malignant behaviors of esophageal cancer cells and its underlying mechanism.METHODSClinical samples were collected to detect the expression of circAKT3. The role of circAKT3 in proliferation, migration, invasion, and apoptosis of esophageal cancer cells was evaluated using Cell Counting Kit-8, wound healing assays, Transwell assays, and fluorescence analysis, respectively. The target of circAKT3 was screened and identified using an online database and luciferase reporter assay. A xenograft nude mouse model was established to investigate the role of circAKT3 in vivo.RESULTS In vitro assays showed that proliferative, migratory, and invasive capacities of esophageal cancer cells were significantly enhanced by circAKT3 overexpression. Furthermore, miR-17-5p was screened as the target of circAKT3, and miR-17-5p antagonized the effects of circAKT3 on esophageal cancer cells. Moreover, we identified RHOC and STAT3 as the direct target molecules of miR-17-5p, and circAKT3 facilitated expression of RHOC and STAT3 by inhibiting miR-17-5p. In vivo assays showed circAKT3 knockdown inhibited growth of esophageal cancer.CONCLUSIONCircAKT3 contributed to the malignant behaviors of esophageal cancer in vitro and in vivo by sponging miR-17-5p thus providing a potential target for treatment of esophageal cancer.

Knockdown of RhoC Inhibits Oral Squamous Cell Carcinoma Cell Invasion and Metastasis via Regulation of HMGA2.

Ras homolog family member C (RhoC) is an important component of intracellular signal transduction and its overexpression has been reported to be involved in regulating tumor proliferation, invasion, and metastasis in various malignant tumors. However, its role and underlying mechanism in oral squamous cell carcinoma (OSCC) still remain obscure. In our study, RhoC expression, its relation with clinical stages, and survival rate in OSCC were analyzed using datasets from The Cancer Genome Atlas (TCGA). Next, a RhoC knockdown cell model was established in vitro, and the effects of RhoC knockdown in OSCC cells were detected by the MTT assay, colony formation assay, transwell invasion assay, scratch assay, and F-actin phalloidin staining. An in vivo tongue-xenografted nude mouse model was established to measure the effects of knockdown of RhoC on tumor cell growth and lymph node metastasis. A mechanism study was conducted by real-time PCR and immunocytochemistry. The results of TCGA analysis showed that RhoC was overexpressed in OSCC tumor tissues. In vitro assays indicated that knockdown of RhoC did not have much effect on OSCC cell growth but significantly suppressed cell colony formation, invasion, and migration abilities, and F-actin polymerization was also reduced. The tongue-xenografted in vivo model demonstrated that knockdown of RhoC suppressed OSCC cell growth and inhibited metastasis to the superficial cervical lymph nodes. Further mechanism studies showed that knockdown of RhoC downregulated HMGA2 expression, and HMGA2 expression was highly correlated with RhoC expression in OSCC tumor tissues via the analysis of TCGA datasets. Overall, our study showed that knockdown of RhoC inhibited OSCC cells invasion and migration in vitro and OSCC cell growth and lymph node metastasis in vivo. Moreover, the potential mechanisms involved in these activities may be related to the regulation of HMGA2 expression. The RhoC gene could serve as a promising therapeutic target for OSCCs in the future.