Loss of p57 expression and RhoA overexpression are associated with poor survival of patients with hepatocellular carcinoma. Oncol Rep. 2013;30:1707-1714. [PMID: 23842948 DOI: 10.3892/or.2013.2608]

Impact of RhoA overexpression on clinical outcomes in cervical squamous cell carcinoma treated with concurrent chemoradiotherapy

The Rho-associated coiled-coil-containing protein kinase (ROCK) pathway is known to influence metastasis in several cancers; however, the impact of the pathway on clinical outcomes in patients undergoing radiotherapy remains unknown. In the present study, the expression of RhoA, RhoC, ROCK-1, ROCK-2 and p53 was immunohistochemically evaluated using biopsy specimens obtained from 49 patients with stage II-III cervical squamous cell carcinoma treated with concurrent chemoradiotherapy (CCRT). The relationship between the expression of these proteins and patient outcomes was investigated. RhoA overexpression was associated with significantly impaired disease-free survival and distant metastasis-free survival (P = 0.045 and P = 0.041, respectively) in stage III cancer patients. No differences in survival were observed based on the expression of the other proteins among stage III cancer patients. In stage II cancer patients, no differences in survival were noted based on the expression of any of the proteins. The expression of RhoA was able to successfully differentiate cervical cancer patients with distant metastasis after CCRT. This information may help stratify patients according to the risk of metastasis, thereby leading to the potential to provide individualized treatment.

Overexpression of Pin1 and rho signaling partners correlates with metastatic behavior and poor recurrence-free survival of hepatocellular carcinoma patients

Background

Identification of molecular markers for early detection or prediction of metastasis is crucial for both management of HCC patient postoperative treatment and identify new therapeutic targets to inhibit HCC progression and metastasis. In the current study, we investigated the clinical correlation between Pin1, RhoA and RhoC and their association with HCC metastasis.

Methods

Using a randomized study design of primary HCC samples from 139 patients, we determined messenger RNA expression of Pin1, RhoA and RhoC and their prognostic value.

Results

Our findings demonstrated for the first time the clinical correlation of Pin1 in HCC metastasis. Pin1, RhoA and RhoC transcript levels were significantly higher in HCC specimens when compared with the paired adjacent non-tumorous liver. Pin1 overexpression was closely correlated with that of RhoA (R = 0.562, p < 0.001) and RhoC (R = 0.529, p < 0.001), and their co-overexpressions correlated with metastatic HCC (p = 0.000012) and poor recurrence-free survival of HCC patients (p < 0.00001), which showed better prognostic significance than either Pin1, RhoA or RhoC overexpression alone. Co-overexpressions of Pin1 + RhoA/RhoC were also an independent factor for predicting development of metastasis after curative resection in our multivariate regression model (p < 0.001).

Conclusion

Pin1, RhoA and RhoC co-overexpressions are prognostic factor for metastatic HCC and predict poor recurrence-free survival.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5919-3) contains supplementary material, which is available to authorized users.

P57-mediated autophagy promotes the efficacy of EGFR inhibitors in hepatocellular carcinoma

BACKGROUND & AIMS

Resistance to EGFR-targeted therapy is a major obstacle in hepatocellular carcinoma (HCC) treatment, but its underlying mechanism remains unclear. Autophagy plays a vital role in antitumour treatment. Our previous study suggested that p57 is associated with autophagy and cisplatin resistance. The present study aimed to investigate whether p57 can enhance the sensitivity of HCC cells to Erlotinib (Er)/Cetuximab(C-225) and further explore the potential mechanisms of Er/C-225 resistance.

METHODS

HCC cells were transfected with pIRES2-EGFP-p57 and pIRES2-EGFP-nc, accompanied by Er/C-225 treatment. Cell viability was detected by an Annexin apoptosis kit and MTT assay. Xenograft experiments were performed to study the function of p57 in the treatment of Er/C-225 in vivo. The level of autophagy was determined by analysis of the appearance of autophagic vacuoles. Western blotting was used to investigate the potential pathways involved.

RESULTS

Up-regulation of p57 decreased the level of Er/C-225-induced autophagy and enhanced the decrease in Er/C-225-induced cell viability. P57 overexpression combined with CQ treatment further enhanced the therapeutic efficiency of Er/C-225. The xenograft experiment verified that p57 up-regulation sensitizes HCC cells to Er/C-225. Moreover, a mechanistic investigation demonstrated that the up-regulation of p57 resulted in a decrease of LC3B-II and beclin-1, and an increase in p-PI3K, p-AKT and p-mTOR protein expressions.

CONCLUSIONS

Through activating the PI3K/AKT/mTOR signalling pathway, p57 can reverse Er/C-225-induced autophagy, and thereby increase the therapeutic efficiency of Er/C-225 treatment. Given these results, p57 up-regulation may be applicable as a therapeutic strategy to improve EGFR-targeted therapy in HCC.

Long non-coding RNA LUCAT1 is associated with poor prognosis in human non-small lung cancer and regulates cell proliferation via epigenetically repressing p21 and p57 expression

Recently, long non-coding RNAs (lncRNAs) have been recognized as playing key roles in regulating cellular processes, such as proliferation, invasion, and metastasis. These lncRNAs have been shown to be abnormally expressed in tumorigenic processes. However, the role and clinical relevance of LUCAT1 in non-small-cell lung cancer (NSCLC) remain unclear. In this study, we found that the expression of LUCAT1 was significantly up-regulated in NSCLC tissues compared to non-tumor tissues, and its expression was associated with tumor size, tumor–node–metastasis (TNM) stage and overall survival (OS). Further experiments showed that LUCAT1 knockdown inhibited cell proliferation both in vitro and in vivo. Mechanistic investigations showed that LUCAT1 plays a key role in G0/G1 arrest. We further demonstrated that LUCAT1 was associated with polycomb repressor complexes (PRC2) and that this association was required for epigenetically repression of p21 and p57, thus contributing to the regulation of NSCLC cell cycle and proliferation. In summary, our results show that LUCAT1 could regulate tumorigenesis of NSCLC and be biomarker for poor prognosis in NSCLC.

Keap1 Inhibits Metastatic Properties of NSCLC Cells by Stabilizing Architectures of F-Actin and Focal Adhesions

Low expression of the tumor suppressor Kelch-like ECH-associated protein 1 (KEAP1) in non-small cell lung cancer (NSCLC) often results in higher malignant biological behavior and poor prognosis; however, the underlying mechanism remains unclear. The present study demonstrates that overexpression of Keap1 significantly suppresses migration and invasion of three different lung cancer cells (A549, H460, and H1299). Highly expressed Keap1, compared with the control, promotes formation of multiple stress fibers with larger mature focal adhesion complexes in the cytoplasm where only fine focal adhesions were observed in the membrane under control conditions. RhoA activity significantly increased when Keap1 was overexpressed, whereas Myosin 9b expression was reduced but could be rescued by proteasome inhibition. Noticeably, mouse tumor xenografts with Keap1 overexpression were smaller in size and less metastatic relative to the control group. Taken together, these results demonstrate that Keap1 stabilizes F-actin cytoskeleton structures and inhibits focal adhesion turnover, thereby restraining the migration and invasion of NSCLC. Therefore, increasing Keap1 or targeting its downstream molecules might provide potential therapeutic benefits for the treatment of patients with NSCLC.Implications: This study provides mechanistic insight on the metastatic process in NSCLC and suggests that Keap1 and its downstream molecules may be valuable drug targets for NSCLC patients. Mol Cancer Res; 16(3); 508-16. ©2018 AACR.

Nrf2 promotes progression of non-small cell lung cancer through activating autophagy

The transcription factor, NFE2-related factor 2 (Nrf2) and autophagy have been implicated in the oxidative-stress response during tumor evolution. However, few studies focus on crosstalk between Nrf2 and autophagy in cancer progression of non-small cell lung cancer (NSCLC). Herein, we evaluated the effect of Nrf2 on autophagy in NSCLC and their role in development of NSCLC. Effect of Nrf2 on overal survival (OS) of NSCLC patients were evaluated. Cell biological behaviors in response to Nrf2 were evaluated by MTT, colony formation assay and flow cytometry. Effect of 3-MA (a classical inhibitor of autophagy) on 95D-Nrf2 cells was also analyzed using flow cytometry. After up/down-regulating Nrf2 in NSCLC cell lines, expression of autophagy-related proteins were evaluated with western blot analysis. The results revealed that Nrf2 was an independent prognositc factor negtively associated with OS of NSCLC patients. Elevated Nrf2 expression promotes NSCLC progression, enhancing the escape of tumor cells from apoptosis in vivo and in vitro. Double staining with Annexin V-APC and 7-AAD showed that the proportions of apoptotic cells in 95D-Nrf2 cells were gradually increased after the addition of 3-MA. Importently, Nrf2 induced autophagosome formation and enhanced autophagic activity, which subsequently inhibits NSCLC cell apoptosis. In conclusion, our present study demonstrates that Nrf2 promotes progression of non-small cell lung cancer through activating autophagy. It provides novel insights into Nrf2-mediated of cell proliferation in NSCLC and may facilitate therapeutic development against NSCLC.

Analysis of transcription profile to reveal altered signaling pathways following the overexpression of human desumoylating isopeptidase 2 in pancreatic cancer cells

Human desumoylating isopeptidase 2 (DESI-2) is a member of the DESI family and contains a conserved PPPDE1 domain. Previous studies have demonstrated that DESI-2 overexpression may induce cell apoptosis. In the present study, differentially expressed genes were analyzed using a transcription microarray in DESI-2 overexpressing PANC-1 pancreatic cancer cells. A total of 45,033 genes were examined by microarray, which identified 1,766 upregulated and 1,643 downregulated genes. A series of altered signaling pathways were analyzed, in which certain essential signaling factors, including retinoid X receptor (RXR), BH3 interacting-domain death agonist, Ras homolog gene family member A (RhoA) and Rho-associated protein kinase, were further investigated at the protein level. The release of cytochrome c and the activation of caspase-3 were also detected by western blot analysis. Immunohistochemistry further revealed the expression features of RXR and RhoA in pancreatic ductal adenocarcinoma tissues with various DESI-2 expression levels. The results serve as a valuable reference for the further elucidation of the functions of DESI-2 in pancreatic cancer.

RhoB Acts as a Tumor Suppressor That Inhibits Malignancy of Clear Cell Renal Cell Carcinoma

This study aims to investigate the biological role of RhoB in clear cell renal cell carcinoma (ccRCC). The expression of RhoB was examined in specimens of patients and cell lines by Western blot and Immunohistochemistry. The correlation between RhoB expression and clinicopathologic variables was also analyzed. The effects of RhoB on cell proliferation, cell cycle, cell apoptosis, and invasion/migration were detected by over-expression and knockdown of RhoB level in ccRCC cells via plasmids and RNAi. The results showed that RhoB was low-expressed in ccRCC surgical specimens and cell lines compared with adjacent normal renal tissues and normal human renal proximal tubular epithelial cell lines (HKC), and its protein expression level was significantly associated with the tumor pathologic parameter embracing tumor size(P = 0.0157), pT stage(P = 0.0035), TNM stage(P = 0.0024) and Fuhrman tumor grade(P = 0.0008). Further, over-expression of RhoB remarkably inhibited the cancer cell proliferation, colony formation and promoted cancer cell apoptosis, and aslo reduced the invasion and migration ability of ccRCC cells. Interestingly, up-regulation of RhoB could induce cell cycle arrest in G2/M phase and led to cell cycle regulators(CyclineB1,CDK1) and pro-apoptotic protein(casp3,casp9) aberrant expression. Moreover, knockdown of RhoB in HKC cells promoted cell proliferation and migration. Taken together, our study indicates that RhoB expression is decreased in ccRCC carcinogenesis and progression. Up-regulation of RhoB significantly inhibits ccRCC cell malignant phenotype. These findings show that RhoB may play a tumor suppressive role in ccRCC cells, raising its potential value in futural therapeutic target for the patients of ccRCC.

MicroRNA-146a inhibits cell migration and invasion by targeting RhoA in breast cancer

MicroRNAs (miRNAs) function as genetic modulators that regulate gene expression and are involved in a wide range of biological roles, including tumor cell migration and invasion. In the present study, we demonstrated that the migration and invasion activity in MDA-MB-231 breast cancer cells could be directly influenced by altering miR-146a expression. The expression of RhoA and miR-146a in the breast cancer cells showed an inverse correlation. Upregulation of miR-146a in the MDA-MB‑231 breast cancer cells by transfection of miR-146a mimics resulted in decreased RhoA protein levels. Conversely, downregulation of miR-146a by transfection of miR-146a inhibitor resulted in increased RhoA protein levels. To confirm the fact that RhoA is a potential target of miR-146a, luciferase reporter containing the RhoA 3' untranslated region (3'UTR) was constructed. The results demonstrated that the luciferase reporter activity was reduced after overexpression of miR-146a. Moreover, the luciferase reporter which was constructed with the RhoA 3'UTR mutant did not show significantly altered luciferase reporter activity. Furthermore, after treatment with the RhoA inhibitor exoenzyme C3 transferase protein, the migratory capacity of the MDA-MB-231 cells was not significantly altered even though the amount of miR-146a was changed. Our results indicate that miR-146a functions as a tumor suppressor in breast cancer cells. Downregulation of the expression of miR-146a increased the migration of MDA-MB-231 cells, due to the upregulation of RhoA expression.

The Correlation Between RhoA Expression and Clinicopathological Characteristics in Gastric Cancer Patients After Curative Surgery

BACKGROUND

The expression of RhoA, a member of the ras homologue family, is reported to be involved in tumorigenesis in some cancers; however, its prognostic value in gastric cancer is controversial.

METHODS

Between April 1988 and January 2005, a total of 206 gastric cancer patients receiving curative surgery were enrolled in this study. Immunohistochemical staining of the RhoA protein was performed, and the clinicopathological characteristics and initial recurrence patterns were compared between low RhoA expression (n = 55) and high RhoA expression (n = 151) gastric cancer patients.

RESULTS

For intestinal-type (n = 134) gastric cancer, there is no significant difference between the clinicopathological characteristics and RhoA expression. However, for diffuse-type (n = 82) gastric cancer, high RhoA expression was associated with more advanced pathological N category compared to low RhoA expression. A multivariate analysis revealed that age, pathological T and N categories, and RhoA expression were independent prognostic factors for overall survival after curative surgery. For all patients, the five-year overall survival rates and disease-free survival rates were higher in patients with low RhoA expression compared to those with high RhoA expression, which was observed in diffuse-type gastric cancer, not in intestinal-type gastric cancer. With regard to the initial recurrence pattern, patients with high RhoA expression had more distant metastasis compared to those with low RhoA expression, especially more liver metastasis.

CONCLUSIONS

RhoA expression is an independent prognostic factor for gastric cancer, especially for diffuse-type. We should be aware of liver metastasis during the follow-up of gastric cancer with high RhoA expression.

High Skp2/Low p57(Kip2) Expression is Associated with Poor Prognosis in Human Breast Carcinoma

Downregulation of p57^Kip2 is involved in tumor progression, and S-phase kinase-associated protein 2 (Skp2) is an E3 ligase that regulates a variety of cell cycle proteins. However, the prognostic value of p57^Kip2 and its correlation with Skp2 in breast cancer have not been fully elucidated. Here we report our study on the expression of p57^Kip2 and Skp2 in 102 breast cancer patients by immunohistochemistry, and analysis of clinicopathologic parameters in relation to patient prognosis. The expression of p57^Kip2 was negatively associated with Skp2 expression in breast cancer (r = −0.26, P = 0.009). Kaplan–Meier analysis indicated that both high Skp2 and low p57^Kip2 correlated with poor disease-free survival (DFS) (P = 0.05), and a group with the combination of high Skp2/low p57^Kip2 demonstrated even worse DFS (log-rank = 21.118, P < 0.001). In addition, univariate analysis showed that Skp2, p57^Kip2, histological grade, lymph node metastasis, and estrogen and progesterone receptors (ER and PR) were all associated with DFS, and multivariate analysis revealed that lymph node metastasis and Skp2 were independent prognostic biomarkers. The correlation between p57 and Skp2 was further demonstrated in multiple breast cancer cell lines and cell cycle phases. Half-life and immunoprecipitation (IP) experiments indicated that Skp2 directly interacts with p57^Kip2 and promotes its degradation, rather than its mutant p57^Kip2 (T310A). Overall, our findings demonstrate that Skp2 directly degrades p57^Kip2, and an inverse correlation between these proteins (high skp2/low p57^Kip2) is associated with poor prognosis in breast cancer. Thus, our results indicate a combined prognostic value of these markers in breast cancer diagnosis and treatment.

Management of hepatocellular carcinoma: Predictive value of immunohistochemical markers for postoperative survival

Hepatocellular carcinoma (HCC) accounts for over 90% of all primary liver cancers. With an ever increasing incidence trend year by year, it has become the third most common cause of death from cancer worldwide. Hepatic resection is generally considered to be one of the most effective therapies for HCC patients, however, there is a high risk of recurrence in postoperative HCC. In clinical practice, there exists an urgent need for valid prognostic markers to identify patients with prognosis, hence the importance of studies on prognostic markers in improving the prediction of HCC prognosis. This review focuses on the most promising immunohistochemical prognostic markers in predicting the postoperative survival of HCC patients.

SDF-1/CXCR4 promotes epithelial-mesenchymal transition and progression of colorectal cancer by activation of the Wnt/β-catenin signaling pathway

Stromal cell-derived factor 1 (SDF-1) and its receptor, CXCR4, play an important role in angiogenesis and are associated with tumor progression. This study aimed to investigate the role of SDF-1/CXCR4-mediated epithelial-mesenchymal transition (EMT) and the progression of colorectal cancer (CRC) as well as the underlying mechanisms. The data showed that expression of CXCR4 and β-catenin mRNA and protein was significantly higher in CRC tissues than in distant normal tissues. CXCR4 expression was associated with β-catenin expression in CRC tissues, whereas high CXCR4 expression was strongly associated with low E-cadherin, high N-cadherin, and high vimentin expression, suggesting a cross talk between the SDF-1/CXCR4 axis and Wnt/β-catenin signaling pathway in CRC. In vitro, SDF-1 induced CXCR4-positive colorectal cancer cell invasion and EMT by activation of the Wnt/β-catenin signaling pathway. In contrast, SDF-1/CXCR4 axis activation-induced colorectal cancer invasion and EMT was effectively inhibited by the Wnt signaling pathway inhibitor Dickkopf-1. In conclusion, CXCR4-promoted CRC progression and EMT were regulated by the Wnt/β-catenin signaling pathway. Thus, targeting of the SDF-1/CXCR4 axis could have clinical applications in suppressing CRC progression.

MicroRNA-122 triggers mesenchymal-epithelial transition and suppresses hepatocellular carcinoma cell motility and invasion by targeting RhoA

The loss of microRNA-122 (miR-122) expression is strongly associated with increased invasion and metastasis, and poor prognosis of hepatocellular carcinoma (HCC), however, the underlying mechanisms remain poorly understood. In the present study, we observed that miR-122 over-expression in HCC cell lines Sk-hep-1 and Bel-7402 triggered the mesenchymal-epithelial transition (MET), as demonstrated by epithelial-like morphological changes, up-regulated epithelial proteins (E-cadherin, ZO-1, α-catenin, occludin, BVES, and MST4), and down-regulated mesenchymal proteins (vimentin and fibronectin). The over-expression of miRNA-122 also caused cytoskeleton disruption, RhoA/Rock pathway inactivation, enhanced cell adhesion, and suppression of migration and invasion of Sk-hep-1 and Bel-7402 cells, whereas, these effects could be reversed through miR-122 inhibition. Additional studies demonstrated that the inhibition of wild-type RhoA function induced MET and inhibited cell migration and invasion, while RhoA over-expression reversed miR-122-induced MET and inhibition of migration and invasion of HCC cells, suggesting that miR-122 induced MET and suppressed the migration and invasion of HCC cells by targeting RhoA. Moreover, our results demonstrated that HNF4α up-regulated its target gene miR-122 that subsequently induced MET and inhibited cell migration and invasion, whereas miR-122 inhibition reversed these HNF4α-induced phenotypes. These results revealed functional and mechanistic links among the tumor suppressors HNF4α, miR-122, and RhoA in EMT and invasive and metastatic phenotypes of HCC. Taken together, our study provides the first evidence that the HNF4α/miR-122/RhoA axis negatively regulates EMT and the migration and invasion of HCC cells.