389

RHOC

ras homolog family member C;RHOC;ras homolog family member C

RAS-related homolog 9|oncogene RHO H9|ras homolog gene family, member C|rho cDNA clone 9|rho-related GTP-binding protein RhoC|rhoC GTPase|small GTP binding protein RhoC

1p13.1

protein-coding

OBJECTIVE: To investigate the expression of RhoC in breast cancer cells with different metastatic potential and its correlation with invasiveness. METHODS: expression of RhoC mRNA and protein in human breast cancer cells MCF-7 with low metastatic potential and MDA-MB-231 with high metastatic potential was detected by RT-PCR, Western blot, immunohistochemistry and immunofluorescence staining. Eukaryotic expression plasmids of RhoC were constructed and transfected into MCF-7 cells. The biological effects were observed, including in vitro invasion by Boyden charmber assay, motility by would healing assay, alteration of microfilament network by TRTIC-phalloidin staining and expression of p-Akt by Western blot assay. RESULTS: The expression levels of RhoC mRNA and protein varied in the two different metastatic breast cancer cell lines. RhoC was significantly up-regulated in the highly metastatic cells in comparison to the weakly metastatic counterpart (P < 0.01). As shown by Boyden charmber assay, the invasive capacity of transfected cells overexpressing RhoC was significantly promoted as reflected by more penetrating cells (56.88 +/- 4.18) than that of the antisense transcripts (23.12 +/- 3.22), the negative (23.77 +/- 3.64) and blank controls (28.44 +/- 2.48). Further study by would healing assay indicated that cells overexpressing RhoC were more motile in actin-based active movement. The wound healing ratio after 24 h of the sense transcripts, antisense transcripts, negative controls and blank controls was 58.28% +/- 2.14%, 22.36% +/- 2.73%, 28.23% +/- 2.62%, 30.18% +/- 2.86%, respectively. The TRITC-phalloidin staining revealed less actin filament bundles and a reorganized cytoskeleton within the sense transcripts. In addition, p-Akt expression level was upregulated in the sense transcripts. CONCLUSION: RhoC overexpression may promote the invasive capacity of human breast cancer cells in vitro and its expression level is positively correlated with the metastatic capacity of those cells. So RhoC may be a potential target in the development of a novel strategy for treating metastasis of breast cancer.

Understanding the molecular alterations that confer cancer cells with motile, metastatic properties is needed to improve patient survival. Here, we report that p38gamma motogen-activated protein kinase regulates breast cancer cell motility and metastasis, in part, by controlling expression of the metastasis-associated small GTPase RhoC. This p38gamma-RhoC regulatory connection was mediated by a novel mechanism of modulating RhoC ubiquitination. This relationship persisted across multiple cell lines and in clinical breast cancer specimens. Using a computational mechanical model based on the finite element method, we showed that p38gamma-mediated cytoskeletal changes are sufficient to control cell motility. This model predicted novel dynamics of leading edge actin protrusions, which were experimentally verified and established to be closely related to cell shape and cytoskeletal morphology. Clinical relevance was supported by evidence that elevated expression of p38gamma is associated with lower overall survival of patients with breast cancer. Taken together, our results offer a detailed characterization of how p38gamma contributes to breast cancer progression. Herein we present a new mechanics-based analysis of cell motility, and report on the discovery of a leading edge behavior in motile cells to accommodate modified cytoskeletal architecture. In summary, these findings not only identify a novel mechanism for regulating RhoC expression but also advance p38gamma as a candidate therapeutic target.

cancer stem cells (CSCs) have been shown to promote tumorigenesis of many tumor types, including breast, although their relevance to cancer metastasis remains unclear. While subpopulations of CSCs required for metastasis have been identified, to date there are no known molecular regulators of breast CSC (BCSC) metastasis. Here we identify RhoC GTPase as an important regulator of BCSC metastasis, and present evidence suggesting that RhoC also modulates the frequency of BCSCs within a population. Using an orthotopic xenograft model of spontaneous metastasis we discover that RhoC is both necessary and sufficient to promote SUM149 and MCF-10A BCSC metastasis--often independent from primary tumor formation--and can even induce metastasis of non-BCSCs within these cell lines. The relationship between RhoC and BCSCs persists in breast cancer patients, as expression of RhoC and the BCSC marker ALDH1 are highly correlated in clinical specimens. These results suggest new avenues to combating the deadliest cells driving the most lethal stage of breast cancer progression.

OBJECTIVE: To detect the expression of RhoC and Ki67 in squamous carcinoma of cervix and to reveal the correlation of RhoC and Ki67 with clinic pathological parameters of cervix carcinoma. METHODS: The expressions of RhoC and Ki67 were evaluated in 26 cases of cervical intraepithelial neoplasia (CIN) and 57 cases of squamous carcinoma of cervix(SCC) by immunohistochemistry, while 14 cases of normal cervical epithelium(NCE) were taken as control. RESULTS: Immunohistochemical staining demonstrated RhoC expression in 82.46% (47/57) of SCC, 15.38% (2/13) of CIN II/III, and negative expression in NCE and CIN I. The positive rate of RhoC expression in SCC was significantly higher than that in NCE and CIN (P < 0.05). The expression of RhoC in SCC was significantly correlated with pelvic lymph node metastasis and depth of stroma infiltration, but not correlated with age, FIGO staging,histologic grade and vascular space involvement. The positive rates of Ki67 expression in NCE, CIN I, CIN II/III and SCC were 28.57%, 38.46%, 100% and 96.49% respectively. The positive rates of Ki67 expression in SCC and CIN II/III were significantly higher than those in NCE and CIN I (P < 0.05). The expression of Ki67 in SCC was not correlated with the major clinic pathological parameters. There was no obvious relationship between the expression of RhoC gene and Ki67 antigen in SCC (P > 0. 05). CONCLUSIONS: The overexpression of RhoC may play an important role in the invasion and metastasis of SCC. RhoC may be a potential marker to identify SCC patients with high risk of invasion and metastasis.

BACKGROUND: Ras homologous (Rho) family GTPases play a pivotal role in the regulation of numerous cellular functions associated with malignant transformation and metastasis. To evaluate the role of these GTPases in colorectal cancer, the mRNA expression levels in matched sets of tumor and non-tumor tissues from surgical specimens were analyzed. The relationship between the mRNA levels in tumor tissues to the clinicopathological features was also assessed. METHODS: A total of 68 patients with colorectal carcinoma were recruited and the levels of RhoA and RhoC mRNA transcripts in cancer, paratumoral and normal tissues were characterized by quantitative real-time polymerase chain reaction (QRT-PCR). Their correlation to clinical histopathological parameters was analyzed. RESULTS: The levels of RhoA and RhoC mRNA transcripts in carcinoma tissues were significantly higher than those in the matched paratumor and normal tissues from the same patient (p<0.05). The expression levels of both genes were significantly correlated with metastasis of cancer cells to lymph nodes and liver (p<0.05). The levels of RhoA expression were significantly correlated with the histopathological degree of cancer, while the expression of RhoC was correlated with the extent of local invasion to intestine. CONCLUSIONS: This is the first study with QRT-PCR to examine the expressions of RhoA and RhoC genes in colorectal carcinoma of Chinese patients. The significantly up-regulated RhoA and RhoC expressions suggest that they may contribute to the initiation, development, invasion and metastasis of colorectal carcinoma in Chinese patients.

PKN3 is an AGC-family protein kinase implicated in growth of metastatic prostate cancer cells with phosphoinositide 3-kinase pathway deregulation. The molecular mechanism, however, by which PKN3 contributes to malignant growth and tumorigenesis is not well understood. Using orthotopic mouse tumor models, we now show that inducible knockdown of PKN3 protein not only blocks metastasis, but also impairs primary prostate and breast tumor growth. Correspondingly, overexpression of exogenous PKN3 in breast cancer cells further increases their malignant behavior and invasiveness in-vitro. Mechanistically, we demonstrate that PKN3 physically interacts with Rho-family GTPases, and preferentially with RhoC, a known mediator of tumor invasion and metastasis in epithelial cancers. Likewise, RhoC predominantly associates with PKN3 compared to its closely related PKN family members. Unlike the majority of Rho GTPases and PKN molecules, which are ubiquitously expressed, both PKN3 and RhoC show limited expression in normal tissues and become upregulated in late-stage malignancies. Since PKN3 catalytic activity is increased in the presence of Rho GTPases, the co-expression and preferential interaction of PKN3 and RhoC in tumor cells are functionally relevant. Our findings provide novel insight into the regulation and function of PKN3 and suggest that the PKN3-RhoC complex represents an attractive therapeutic target in late-stage malignancies.

AIM: To investigate the expression and significance of G3BP and RhoC proteins in esophageal squamous carcinoma (ESC). METHODS: The expression of G3BP and Rhoc proteins in 80 cases of ESC was detected by immunohistochemistry. The relationship was studied between the expression of the two proteins and tumor size, differentiation degree, TNM stage, lymph node metastasis and prognosis of ESC. RESULTS: The positive expression rate of G3BP in ESC was 71.25%; and the rate in the lymph node metastasis group was significantly higher than that in the non-lymph node metastasis group (Z = -2.283, P = 0.022), but no relations were found between G3BP expression and tumor size, differentiation degree and TNM stage (P > 0.05). The group with G3BP positive expression had shorter survival time than the group with G3BP negative expression (P = 0.000). The positive expression rate of RhoC in ESC was 66.25%; and the rate in the lymph node metastasis group was significantly higher than that in the non-lymph node metastasis group (Z = -2.115, P < 0.05), but no relations were found between RhoC expression and tumor size, differentiation degree and TNM stage (P > 0.05). The RhoC positive expression group had a shorter survival time than the RhoC negative expression group (P < 0.001. The expression of G3BP protein correlated positively with the expression of RhoC in ESC tissues (rs = 0.656, P < 0.001). CONCLUSION: The expression of G3BP and RhoC protein is closely related to the lymph node metastasis and survival in ESC patients. G3BP and RhoC proteins can be considered as predictors of prognosis in ESC patients.

OBJECTIVES: RHOC, a member of the RAS-related small GTPase protein family, regulates cytoskeletal structures and has the potential to transform cultured cells. It has recently been reported that RHOC contributes to the metastatic phenotype of melanoma cells. The purpose of this study was to clarify its biological relevance to gastric carcinogenesis and metastasis. METHODS: We examined the expression of RHOC by quantitative RT-PCR in 51 cases of gastric carcinoma tissues from prior surgical cases (intestinal type: 24 cases, diffuse type: 27 cases) and in 8 gastric carcinoma cell lines. RESULTS: RHOC expression levels in primary tumors were significantly higher in cases with metastasis than in those without metastasis (p = 0.0202; Mann-Whitney U test). RHOC expression levels in primary tumor and their metastatic tumors were significantly higher than their corresponding nonneoplastic mucosa (p = 0.0357, and 0.0173, respectively; Wilcoxon signed rank test). RHOC mRNA expression was confirmed in the gastric carcinoma cell lines. CONCLUSION: Our findings suggest that elevated expression of the RHOC gene may be involved in the metastasis of gastric carcinomas and may be a good genetic marker for the prediction of a metastatic potential.

Rho family members are known to regulate malignant transformation and motility of cancer cells, but the clinicopathological significance of RhoC remains unclear yet in the case of gastric cancer. In this study, we evaluated the protein expression level of RhoC in gastric cancer tissues and cell lines. Results showed that only weak staining of RhoC was detected in 3 of 33 non-tumorous cases by immunohistochemistry. The expression of RhoC was significantly higher in gastric cancer tissues (23/42, 54.8%) than in non-tumorous tissues (p < 0.01). Further analysis demonstrated that RhoC had high specificity (80.0%) in detecting gastric carcinomas with metastatic potential. RhoC was positively expressed in 18 out of 20 metastases (90.0%), even higher than that in primary gastric cancer tissues. Western blot showed that RhoC was up-regulated in five different gastric cancer cell lines but not expressed in SV40-transformed immortal gastric epithelial cell GES-1. Overexpression of RhoC GTPase in GES-1 cells could produce the motile and invasive phenotype but did not alter the monolayer growth rate. To further study the functions of RhoC, we took the powerful siRNA technology to knock down the expression of RhoC in SGC7901 cells. It was shown that down-regulation of RhoC did not affect the proliferation of SGC7901 cells. However, interference of RhoC expression could inhibit migration, invasion, and anchorage-independent growth of SGC7901 cells. In conclusion, RhoC may play a very important role in the metastasis of gastric carcinoma. Therapeutic strategies targeting RhoC and RhoC-mediated pathways may be a novel approach for treating metastasis of gastric cancer.

AIM: To investigate the expression of RhoC gene in hepatocellular carcinoma (HCC) and to evaluate the relationship between RhoC gene expression and invasion and metastasis of HCC. METHODS: mRNA expression level of RhoC gene was examined by reverse transcription-polymerase chain reaction (RT-PCR) in 25 cases of HCC and para-cancerous normal liver tissues. In addition, mutation of RhoC gene was examined by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP). RESULTS: The mRNA expression levels of RhoC in tumor tissues were significantly higher than those in para-cancerous normal liver tissues (1.8+/-1.1 vs 1.0+/-0.7, P<0.01). The metastatic lesions outside of liver also showed significantly higher RhoC mRNA levels than corresponding tumor tissues in liver (3.3+/-0.5 vs 2.0+/-0.7, P<0.01). There were significant associations between RhoC gene expression and certain clinical and pathological findings, including cell differentiation, vein invasion, number of tumor nodes and metastatic lesions. mutation of RhoC gene was not found by PCR-SSCP. CONCLUSION: The RhoC gene may be related to malignant transformation and development of HCC and may play an important role in the invasion and metastasis of HCC by overexpression but not mutation.

Our previous study identified RhoC as an invasion and metastasis marker in hepatocellular carcinoma patients. Recent document suggested RhoGTPase is required for autocrine motility factor signaling. In this study, we questioned whether there is a correlation between expression of autocrine motility factor receptor and RhoC. Furthermore, we questioned whether elevated expression of autocrine motility factor correlates with metastasis and poor prognosis of HCC. The mRNA expression level of AMFR and RhoC were examined by RT-PCR in 25 cases of HCC and pericarcinomatous liver tissues (PCLT). In addition, the correlation between the expression level of AMFR and clinical pathologic parameters was analyzed. Furthermore, follow-up information was collected to evaluate the prognostic value of AMFR for HCC patients. Our results showed that the expression of AMFR and RhoC significantly increased in HCC compared with PCLT; extrahepatic metastatic lesions expressed significantly higher levels of AMFR and RhoC than corresponding intrahepatic HCC tissues. There is a highly significant correlation of AMFR expression levels with tumor vein invasion, number of tumor nodes, and tumor stage. Anticipatively, positive correlation was observed between mRNA expression of AMFR and RhoC gene. Furthermore, the HCC patients with high-expression of AMFR had significant high recurrence/metastasis and shorter survival than those with low-expression of AMFR. Together, our findings suggested a strong correlation between the expression of AMFR and RhoC and also a correlation between overexpression of them and invasion and metastasis of HCC. Furthermore, our data indicated AMFR as a potential prognosis for HCC.

PURPOSE: Hepatocellular carcinoma (HCC) is one of the most deadly human cancers because of its high incidence of metastasis. Our previous work identified a strong correlation between increased expression of RhoC and HCC metastasis. Here, we investigate to define the role of RhoC in HCC metastasis. Furthermore, we sought to determine whether inhibition of the expression of RhoC might block the metastasis of HCC in vivo. EXPERIMENTAL DESIGN: A stable retroviral small interfering RNA approach was employed to selectively knockdown the expression of RhoC in vitro and in vivo. Invasion and migration assay, MTT and fluorescence-activated cell sorting analysis, Rho activity assay, and immunofluorescence staining were carried out to characterize RhoC in vitro. An anti-RhoC retroviral gene delivery BALB/c nude mice model was established to investigate whether knockdown of the expression of RhoC might inhibit the metastasis of HCC in vivo. RESULTS: We confirmed the correlation of RhoC expression and metastatic potentials of HCC cell lines. We also showed that suppression of RhoC expression resulted in inhibition of invasion and migration without an apparent effect on cell survival and proliferation in HCCLM3 cells. Furthermore, a similar effect of RhoC on autotaxin-induced invasion of HCCLM3 cells was also observed. Significantly, we successfully adopted an HCC metastatic mouse model that allowed us to show that knockdown of the RhoC expression resulted in inhibition of metastasis of HCC in vivo for the first time. CONCLUSIONS: Our results show a critical role of RhoC in metastasis of HCC, implicating RhoC as a potential therapeutic target to block HCC metastasis.

BACKGROUND: RhoC overexpression in tumor cells promotes invasive and metastatic behavior. RhoC expression levels have been correlated with tumor progression and metastasis in multiple human cancers. In melanoma, RhoC is upregulated in highly metastatic tumors. Induced expression in melanoma cell lines resulted in invasion and metastasis, whereas inhibition of RhoC reversed the metastatic phenotype both in vitro and in vivo. METHODS: RhoC mRNA and protein expression in two human melanoma cell lines (DX3aza and MeWo) and pooled primary melanocytes were investigated by means of real-time quantitative polymerase chain reaction and western blotting. RhoC protein expression was evaluated in 123 primary cutaneous melanoma samples by the use of immunohistochemistry and correlated with known prognostic features. RESULTS: RhoC upregulation was observed in the highly metastatic DX3aza cell line, whereas in MeWo, only low expression levels could be detected. RhoC expression in primary cutaneous melanoma was strongly associated with thicker and ulcerated tumors. RhoC expression was associated with the presence of lymphatic metastases at the time of diagnosis and shorter disease-free and overall survival rates, without being an independent predictor. CONCLUSION: These results further support a role for RhoC in growth and metastasis of melanoma.

Human pancreatic ductal adenocarcinoma (PDAC) is characterized by early systemic dissemination. Although RhoC has been implicated in cancer cell migration, the relevant underlying molecular mechanisms remain unknown. RhoC has been implicated in the enhancement of cancer cell migration and invasion, with actions which are distinct from RhoA (84% homology), and are possibly attributed to the divergent C-terminus domain. Here, we confirm that RhoC significantly enhances the migratory and invasive properties of pancreatic carcinoma cells. In addition, we show that RhoC over-expression decreases cancer cell adhesion and, in turn, accelerates cellular body movement and focal adhesion turnover, especially, on fibronectin-coated surfaces. Whilst RhoC over-expression did not alter integrin expression patterns, we show that it enhanced integrin alpha5beta1 internalization and re-cycling (trafficking), an effect that was dependent specifically on the C-terminus (180-193 amino acids) of RhoC protein. We also report that RhoC and integrin alpha5beta1 co-localize within the peri-nuclear region of pancreatic tumor cells, and by masking the CAAX motif at the C-terminal of RhoC protein, we were able to abolish this interaction in vitro and in vivo. Co-localization of integrin alpha5beta1 and RhoC was demonstrable in invading cancer cells in 3D-organotypic cultures, and further mimicked in vivo analyses of, spontaneous human, (two distinct sources: operated patients and rapid autopsy programme) and transgenic murine (LSL-KrasG12D/+;LSL-Trp53R172H/+;Pdx-1-Cre), pancreatic cancers. In both cases, co-localization of integrin alpha5beta1 and RhoC correlated with poor differentiation status and metastatic potential. We propose that RhoC facilitates tumor cell invasion and promotes subsequent metastasis, in part, by enhancing integrin alpha5beta1 trafficking. Thus, RhoC may serve as a biomarker and a therapeutic target.

RhoC is a member of the Ras-homologous family of genes which have been implicated in tumorigenesis and tumor progression. However, the exact role of RhoC is controversial and is yet to be clarified. We have examined the effect of RhoC on prostate tumor cells and found that RhoC had no effect on cell proliferation in vitro or on tumor growth in mice. However, RhoC significantly enhanced the metastatic ability of the tumor cells in these animals, suggesting that RhoC affects only the metastasis but not the growth of prostate tumor cells. The results of our immunohistochemical analyses on tumor specimens from 63 patients with prostate cancer indicate that RhoC expression had no significant correlation with Gleason grade. However, the expression of RhoC showed significant positive correlation with both lymph node and distant metastasis, and it was inversely correlated with patient survival. We also found that RhoC significantly augmented the invasion and motility of prostate tumor cells by activating matrix metalloproteinases 2 and 9 (MMP2 and MMP9) in vitro. The results of our antibody array analysis for signal molecules revealed that RhoC significantly activated kinases including mitogen-activated protein kinase (MAPK), focal adhesion kinase (FAK), Akt, and Pyk2. Inhibition of Pyk2 kinase blocked the RhoC-dependent activation of FAK, MAPK, and Akt, followed by the suppression of MMP2 and MMP9. Inhibitors of both MAPK and Akt also significantly blocked the activities of these MMPs. Therefore, our results indicate that RhoC promotes tumor metastasis in prostate cancer by sequential activation of Pyk2, FAK, MAPK, and Akt followed by the up-regulation of MMP2 and MMP9, which results in the stimulation of invasiveness of tumor cells.

OBJECTIVE: To detect the expression of RhoC and Rho kinase 1 (ROCK-1) in prostate carcinoma, and explore the possible mechanism of RhoC/ROCK-1 in the pathogenesis of prostate carcinoma. METHODS: Tissue specimens from 73 patients with prostate carcinoma and corresponding paracancerous tissues were obtained by prostate cancer biopsy or radical prostatectomy. The expression of RhoC/ROCK-1 mRNA was detected by RT-PCR. Western blot and immunohistochemistry were performed to dertect the expression of RhoC/ROCK-1 protein. Eukaryotic expression plasmids of RhoC were constructed and transfected into PC-3M-2B4 cells. p-MAPK and p-Akt were detected by Western bolt. RESULTS: The expression levels of RhoC and ROCK-1 mRNA in the prostate carcinomas were significantly higher than those in corresponding paracancerous tissues [72.6% (53/73) vs. 34.2% (25/73); 68.5% (50/73) vs. 38.4% (28/73), P < 0.01], respectively. The results indicated that RhoC/ROCK-1 mRNA expression had no significant correlation with Gleason grade. However, the expression of RhoC/ROCK-1 mRNA showed a significant positive correlation with distant metastasis. The RhoC/ROCK-1 protein expression in prostate cancer was also higher than corresponding paracancerous tissues, and showed a significant positive correlation with p-MAPK and p-Akt expression levels. In addition, p-MAPK and p-Akt expression levels were up-regulated in the transcripts. CONCLUSION: expression levels of RhoC and ROCK-1 in prostate carcinoma are higher than those in corresponding paracancerous tissues, showing a significant positive correlation with distant metastasis. RhoC/ROCK-1 may be involved in the development, invasion and metastasis of prostate carcinoma.

PURPOSE: Survival rates for squamous cell carcinoma of the head and neck (SCCHN) have remained unchanged for several decades due to local tumor recurrences as well as regional and distant metastases. Recent evidence has shown that RhoC GTPase is overexpressed in stages III and IV regionally metastatic SCCHN compared with stages I and II localized disease. This study evaluated the expression of RhoC in head and neck carcinoma and investigated the prognostic use of this marker on a large cohort of previously untreated patients with SCCHN. EXPERIMENTAL DESIGN: Standard Western blot techniques were used to evaluate RhoC protein expression in nine established head and neck cancer cell lines and in normal oral epithelium. In vivo expression of RhoC in metastatic and nonmetastatic SCCHN was investigated using immunohistochemical analysis on a tissue microarray composed of 113 independent tumor samples. RhoC expression was analyzed as it related to clinical and pathologic variables of interest. RESULTS: Levels of RhoC protein were increased in the SCCHN cell lines compared with normal oral epithelium. The in vivo expression of RhoC correlated with advanced clinical stage and lymph node metastases for the entire patient cohort as well as in small primary tumors (T(1) and T(2)). CONCLUSIONS: This study is the first to examine the expression of RhoC GTPase protein in SCCHN and normal squamous epithelium. It is clear from the results that RhoC is a specific marker of lymph node metastases in patients with this challenging form of carcinoma. RhoC levels seem to identify a subset of patients with early tumor stage primary tumors and high metastatic potential that might benefit from more aggressive therapy. Through continued investigation, blockade of RhoC activity may be a potential target in the development of novel strategies for treating metastases of head and neck cancer.

tumor metastasis is the dominant cause of death in cancer patients, including patients with oral tongue squamous cell carcinoma (TSCC). Previously, we reported that reduced miR-138 level is correlated with enhanced metastatic potential in TSCC cells. Here, we demonstrate that miR-138 suppresses TSCC cell migration and invasion by regulating 2 key genes in the Rho GTPase signaling pathway: RhoC and ROCK2. Direct targeting of miR-138 to specific sequences located in the 3'-untranslated regions of both RhoC and ROCK2 mRNAs was confirmed using luciferase reporter gene assays. Ectopic transfection of miR-138 reduced the expression of both RhoC and ROCK2 in TSCC cells. These reduced expressions, in consequence, led to the reorganization of the stress fibers and the subsequent cell morphology change to a round bleb-like shape as well as the suppression of cell migration and invasion. In contrast, knockdown of miR-138 in TSCC cells enhanced the expression of RhoC and ROCK2, which resulted in an altered, elongated cell morphology, enhanced cell stress fiber formation and accelerated cell migration and invasion. Taken together, our results suggest that miR-138 plays an important role in TSCC cell migration and invasion by concurrently targeting RhoC and ROCK2, and miR-138 may serve as a novel therapeutic target for TSCC patients at risk of metastatic disease.