Effect of RhoC on the epithelial-mesenchymal transition process induced by TGF-β1 in lung adenocarcinoma cells

Investigating Ras homolog gene family member C (RhoC) and Ki67 expression following external beam radiation therapy show increased RhoC expression in relapsing prostate cancer xenografts

Ras homolog gene family member C (RhoC) is a GTPase involved in cell migration, implicated in epithelial-mesenchymal transition and treatment resistance and metastasis of cancer. For example, RhoC has been shown to be involved in resistance to radiation in cervical carcinoma. Here, the effect of X-ray irradiation on RhoC expression in prostate cancer (PCa) xenografts was investigated in both xenografts in regression and relapse. Male BALB/cAnNRj-Foxn1nu/nu mice were inoculated with 4-6 million LNCaP-FGC cells and established xenografts were irradiated with X-rays (200 kV, 1 Gymin-1), 5, 10 or 15 Gy using a Gulmay Medical X-ray system. Expression of RhoC and Ki67, a known proliferation marker, was investigated in xenografts, given 15 Gy, 7 days (midst response as measured by size) or 3 weeks (relapse) post irradiation. Staining was quantified using the Halo software (v2.3.2089.34) with the Indica Labs - cytonuclear v1.6 algorithm. RhoC and Ki67 staining was divided into weak, medium, and strong staining and the percentage of cells stained, single and dual staining, was quantified. The HALO software was further used to classify the tissue in each section so that analysis of RhoC and Ki67 expression in cancer cells, stroma and necrotic areas could be done separately. The results showed that RhoC expression in cancer and stroma cells was significantly higher in relapsed xenografts than in those in regression. This was not seen for Ki67 staining, where the percentage of stained cells were the same in regressing and relapsing tumors. RhoC could be a useful biomarker to confirm relapse following external beam radiation therapy.

pH- and Matrix Metalloproteinase-Responsive Multifunctional Bilayer Microneedles Platform for Treatment of Tinea Pedis

Persistent foot odor and itchiness are common symptoms of tinea pedis, significantly disrupting the daily life of those affected. The cuticular barrier at the site of the tinea pedis is thickened, which impedes the effective penetration of antifungal agents. Additionally, fungi can migrate from the skin surface to deeper tissues, posing challenges in the current clinical treatment for tinea pedis. To effectively treat tinea pedis, we developed a platform of bilayer gelatin methacrylate (GelMA) microneedles (MNs) loaded with salicylic acid (SA) and FK13-a1 (SA/FK13-a1@GelMA MNs). SA/FK13-a1@GelMA MNs exhibit pH- and matrix metalloproteinase (MMP)-responsive properties for efficient drug delivery. The MNs are designed to deliver salicylic acid (SA) deep into the stratum corneum, softening the cuticle and creating microchannels. This process enables the antibacterial peptide FK13-a1 to penetrate through the stratum corneum barrier, facilitating intradermal diffusion and exerting antifungal and anti-inflammatory effects. In severe cases of tinea pedis, heightened local pH levels and MMP activity further accelerate drug release. Our research demonstrates that SA/FK13-a1@GelMA MNs are highly effective against Trichophyton mentagrophytes, Trichophyton rubrum, and Candida albicans. They also reduced stratum corneum thickness, fungal burden, and inflammation in a guinea pig model of tinea pedis induced by T. mentagrophytes. Furthermore, it was discovered that SA/FK13-a1@GelMA MNs exhibit excellent biocompatibility. These findings suggest that SA/FK13-a1@GelMA MNs have significant potential for the clinical treatment of tinea pedis as well as other fungal skin disorders.

TGF-β signaling in health, disease, and therapeutics

Transforming growth factor (TGF)-β is a multifunctional cytokine expressed by almost every tissue and cell type. The signal transduction of TGF-β can stimulate diverse cellular responses and is particularly critical to embryonic development, wound healing, tissue homeostasis, and immune homeostasis in health. The dysfunction of TGF-β can play key roles in many diseases, and numerous targeted therapies have been developed to rectify its pathogenic activity. In the past decades, a large number of studies on TGF-β signaling have been carried out, covering a broad spectrum of topics in health, disease, and therapeutics. Thus, a comprehensive overview of TGF-β signaling is required for a general picture of the studies in this field. In this review, we retrace the research history of TGF-β and introduce the molecular mechanisms regarding its biosynthesis, activation, and signal transduction. We also provide deep insights into the functions of TGF-β signaling in physiological conditions as well as in pathological processes. TGF-β-targeting therapies which have brought fresh hope to the treatment of relevant diseases are highlighted. Through the summary of previous knowledge and recent updates, this review aims to provide a systematic understanding of TGF-β signaling and to attract more attention and interest to this research area.

EMT induces characteristic changes of Rho GTPases and downstream effectors with a mitosis-specific twist

Epithelial-mesenchymal transition (EMT) is a key cellular transformation for many physiological and pathological processes ranging from cancer over wound healing to embryogenesis. Changes in cell migration, cell morphology and cellular contractility were identified as hallmarks of EMT. These cellular properties are known to be tightly regulated by the actin cytoskeleton. EMT-induced changes of actin-cytoskeletal regulation were demonstrated by previous reports of changes of actin cortex mechanics in conjunction with modifications of cortex-associated f-actin and myosin. However, at the current state, the changes of upstream actomyosin signaling that lead to corresponding mechanical and compositional changes of the cortex are not well understood. In this work, we show in breast epithelial cancer cells MCF-7 that EMT results in characteristic changes of the cortical association of Rho-GTPases Rac1, RhoA and RhoC and downstream actin regulators cofilin, mDia1 and Arp2/3. In the light of our findings, we propose that EMT-induced changes in cortical mechanics rely on two hitherto unappreciated signaling paths-i) an interaction between Rac1 and RhoC and ii) an inhibitory effect of Arp2/3 activity on cortical association of myosin II.

High Expression of RhoBTB3 Predicts Favorable Chemothrapy Outcomes in non-M3 Acute Myeloid Leukemia

Background: The expression patterns and prognostic significance of the Rho family GTPases in acute myeloid leukemia have not been systematically studied yet.

Methods: In our study, we analyzed the expression patterns of 21 Rho family GTPases gene members in AML patients based on GEPIA database. 10 gene members with significant differential expression in AML tissue and healthy tissue were selected for subsequent research. Survival curve analysis in TCGA and GEO dataset preliminary showed that RhoBTB3 is related with the prognosis of non-M3 AML patients. The differential expression of RhoBTB3 on AML bone marrow and normal bone marrow was verified by RT-qPCR. We performed Kaplan-Meier survival analysis and Multivariate Cox analysis to assess the prognostic value of RhoBTB3 in non-M3 AML patients with different treatment regimens. Gene functional enrichment analysis of RhoBTB3 was performed using GO, KEGG and PPI network.

Results: The AML patients from TCGA database were partitioned into 2 groups based on different treatment regimens: chemotherapy group and allo-HSCT group. In chemotherapy group, patients with higher expression level of RhoBTB3 showed relatively longer OS and EFS, multivariate Cox analysis revealed high RhoBTB3 mRNA expression as an independent favorable prognostic factor. However, in allo-HSCT group, no significant difference of OS and EFS were found between RhoBTB3 high and low subgroups. Meanwhile, allo-HSCT could circumvent the unfavorable prognosis that was associated with downregulation of RhoBTB3. Functional enrichment analysis showed the association of RhoBTB3 expression with several fundamental physiological components and pathways, including extracellular matrix components, extracellular structure organization, and cytokine-cytokine receptor interaction.

Conclusions: Our study identified RhoBTB3 as a prognostic marker and may aid in the selection of the appropriate treatment options between chemotherapy and allo-HCST in non-M3 AML patients. Further researches are necessary to clarify the involvement of RhoBTB3 in the pathogenesis of AML.

RNF168 promotes RHOC degradation by ubiquitination to restrain gastric cancer progression via decreasing HDAC1 expression

Gastric cancer (GC) is the most common cancer worldwide. Although advances in the treatments, the oncogenic mechanisms are still largely unknown. RNF168 (ring-finger nuclear factor 168) is an important regulator of DNA double-strand break (DSB) repair, and its defects have been involved in the pathogenesis of a number of human diseases including cancer. However, its effects on GC are still unclear. In the study, we demonstrated that RNF168 expression was remarkably down-regulated in human GC tissues, and its low expression showed worse overall survival rate in GC patients. Importantly, we here reported that RNF168 directly interacted with Ras homolog gene family member C (RHOC) and induced its ubiquitination to promote RHOC degradation. RHOC exhibited higher expression in human GC tissues, and its knockdown significantly restrained cell proliferation, migration and invasion in GC cell lines. Moreover, RHOC knockdown led to a significant reduction in GC tumor growth in a xenograft mouse model. Additionally, histone deacetylase 1 (HDAC1) was found to be markedly decreased in GC cells with RHOC knockdown. Intriguingly, RHOC suppression-ameliorated proliferative and migratory ability in GC cells were significantly diminished by HDAC1 over-expression. Our in vivo studies finally confirmed that RHOC inhibition dramatically reduced the lung metastasis in nude mice. Collectively, all our results demonstrated that RNF168 directly interacted with RHOC to induce its degradation via promoting its ubiquitination, contributing to the inhibition of cell proliferation and metastasis in GC through decreasing HDAC1. Thus, targeting RNF168/RHOC/HDAC1 axis might be promising to develop effective therapies for GC treatment.

PCGF3 promotes the proliferation and migration of non-small cell lung cancer cells via the PI3K/AKT signaling pathway

The Polycomb Group Ring Finger 3 (PCGF3) protein has been reported to be significantly upregulated in pancreatic islet tumors and related to signal transduction; however, its detailed mechanisms and biological roles in other tumors, including non-small cell lung cancer (NSCLC), remain unclear. This study investigated the function of PCGF3 in NSCLC and further elucidated its mechanism of action. The immunohistochemical analysis of 86 selected lung cancer tissues revealed that PCGF3 was highly expressed in NSCLC tissues and positively correlated with lymph node metastasis and p-TNM staging. Additionally, PCGF3 promoted cell proliferation in lung cancer by regulating CyclinB1, CyclinD1, and CDK4 expression, and also promoting their migration by regulating RhoA, RhoC, and CDC42. Furthermore, PCGF3 affected both the proliferation and migration of lung cancer cells by regulating the PI3K/AKT pathway, as verified by inhibiting this pathway using LY294002. The findings of this study suggested that PCGF3 is associated with poor prognosis in patients with NSCLC and could therefore be an important biomarker for treating and preventing NSCLC.

The Roles of Tissue Rigidity and Its Underlying Mechanisms in Promoting Tumor Growth

Tissues become more rigid during tumorigenesis and have been identified as a driving factor for tumor growth. Here, we highlight the concept of tissue rigidity, contributing factors that increase tissue rigidity, and mechanisms that promote tumor growth initiated by increased tissue rigidity. Various factors lead to increased tissue rigidity, promoting tumor growth by activating focal adhesion kinase (FAK) and Rho-associated kinase (ROCK). Consequently, result in recruitment of cancer-associated fibroblasts (CAFs), epithelial-mesenchymal transition (EMT) and tumor protection from immunosurveillance. We also discussed the rationale for targeting tumor tissue rigidity and its potential for cancer treatment.

RhoC: a fascinating journey from a cytoskeletal organizer to a Cancer stem cell therapeutic target

Tumor heterogeneity results in differential response to therapy due to the existence of plastic tumor cells, called cancer stem cells (CSCs), which exhibit the property of resistance to therapy, invasion and metastasis. These cells have a distinct, signaling network active at every stage of progression. It is difficult to envisage that the CSCs will have a unique set of signaling pathways regulating every stage of disease progression. Rather, it would be easier to believe that a single pivotal pathway having significant contribution at every stage, which can further turn on a battery of signaling mechanisms specific to that stage, would be instrumental in regulating the signaling network, enabling easy transition from one state to another. In this context, we discuss the role of RhoC which has contributed to several phenotypes during tumor progression.

RhoC (Ras homolog gene family member C) has been widely reported to regulate actin organization. It has been shown to impact the motility of cancer cells, resultantly affecting invasion and metastasis, and has contributed to carcinoma progression of the breast, pancreas, lung, ovaries and cervix, among several others. The most interesting finding has been its indispensable role in metastasis. Also, it has the ability to modulate various other phenotypes like angiogenesis, motility, invasion, metastasis, and anoikis resistance. These observations suggest that RhoC imparts the plasticity required by tumor cells to exhibit such diverse functions based on microenvironmental cues. This was further confirmed by recent reports which show that it regulates cancer stem cells in breast, ovary and head and neck cancers. Studies also suggest that the inhibition of RhoC results in abolition of advanced tumor phenotypes.

Our review throws light on how RhoC, which is capable of modulating various phenotypes may be the apt core signaling candidate regulating disease progression. Additionally, mice studies show that RhoC is not essential for embryogenesis, giving scope for its development as a possible therapeutic target. This review thus stresses on the need to understand the protein and its functioning in greater detail to enable its development as a stem cell marker and a possible therapeutic target.

Ursolic Acid Attenuates TGF-β1-Induced Epithelial-Mesenchymal Transition in NSCLC by Targeting Integrin αVβ5/MMPs Signaling

Transforming growth factor-β1 (TGF-β1)-induced epithelial-mesenchymal transition (EMT) of non-small cell lung cancer (NSCLC) may contribute to tumor metastasis. TGF-β1-induced EMT in H1975 cells (a human NSCLC cell line) resulted in the adoption of mesenchymal responses that were predominantly mediated via the TGF-β1-integrin signaling pathway. Ursolic acid has been previously reported to inhibit tumor growth and metastasis in several cancers. However, whether ursolic acid can attenuate TGF-β1-induced EMT in H1975 cells and its underlying mechanisms remain unknown. In this study, ursolic acid significantly attenuated the TGF-β1-induced decrease in E-cadherin level and elevated the level of N-cadherin. Furthermore, ursolic acid inhibited the mesenchymal-like responses in H1975 cells, including cell migration, invasion, and activity of matrix metallopeptidase (MMP)-2 and -9. Finally, our new findings provided evidence that ursolic acid could inhibit EMT in NSCLC through TGF-β1 signaling pathway-mediated integrin αVβ5 expression, and this might be the potential mechanism of resveratrol on the inhibition of invasion and metastases in NSCLC. We conclude that ursolic acid attenuated TGF-β1-induced EMT in H1975 cells and thus might be a promising therapeutic agent for treating NSCLC.

The protective effects of heat shock protein 22 in lung ischemia-reperfusion injury mice

Lung ischemia-reperfusion injury (LIRI) often results in respiratory insufficiency after pulmonary embolism, lung transplantation, etc. To investigate the role of HSP22 in LIRI mice, ischemia-reperfusion injury was established in the left lung of an HSP22 overexpression transgenic mouse. Twelve HSP22 transgenic (TG) mice and twelve wild-type (WT) mice were randomly divided into 2 groups: the sham-operated group (SO: TG-SO, WT-SO) and the ischemia-reperfusion group (I/R: TG-I/R, WT-I/R), respectively. We tested the PaO₂, W/D ratio, and MDA level; observed morphology changes; and calculated the index of alveolar damage. HSP22 expression was examined in lung tissues of TG and WT C57BL mice by immunohistochemistry. TUNEL assay was performed to measure apoptosis. We found that HSP22 was significantly overexpressed in TG mice. There was no difference in PaO₂ among the four groups. In the I/R group, the W/D ratio, MDA and index of alveolar damage were higher than those in the SO group. Moreover, compared with WT-I/R group, the W/D ratio, MDA and index of alveolar damage in the TG-I/R group were significantly decreased. Apoptosis in the I/R groups was increased compared to that in the SO groups, while apoptosis in the TG-I/R groups was decreased compared to that in the WT-I/R groups. Our results showed that HSP22 TG mice and the LIRI model were successfully established. In addition, HSP22 overexpression has protective effects on LIRI by inhibiting lipid peroxidation and apoptosis.

RhoC/ROCK2 promotes vasculogenic mimicry formation primarily through ERK/MMPs in hepatocellular carcinoma

Vasculogenic mimicry (VM) results in the formation of an alternative circulatory system that can improve the blood supply to multiple malignant tumors, including hepatocellular carcinoma (HCC). However, the potential mechanisms of RhoC/ROCK in VM have not yet been investigated in HCC. Here, RhoC expression was upregulated in HCC tissues, especially the VM-positive (VM+) group, compared to noncancerous tissues (P < 0.01), and patients with high expression of RhoC had shorter survival times (P < 0.001). The knockdown of RhoC via short hairpin RNA (shRNA) in SK-Hep-1 cells significantly decreased VM formation and cell motility. In contrast, cell motility and VM formation were remarkably enhanced when RhoC was overexpressed in HepG2 cells. To further assess the potential role of ROCK1 and ROCK2 on VM, we stably knocked down ROCK1 or ROCK2 in MHCC97H cells. Compared to ROCK1 shRNA, ROCK2 shRNA could largely affect VM formation, cell motility and the key VM factors, as well as the epithelial-mesenchymal transition (EMT) markers in vitro and in vivo. Moreover, p-ERK, p-MEK, p-FAK, p-paxillin, MT1-MMP and MMP2 levels were clearly altered following the overexpression of RhoC, but ROCK2 shRNA had little effect on the expression of p-FAK, which indicated that RhoC regulates FAK/paxillin signaling, but not through ROCK2. In conclusion, our results show that RhoC/ROCK2 may have a major effect on VM in HCC via ERK/MMPs signaling and might be a potential therapeutic target for the treatment of HCC.

Mechanistic regulation of epithelial-to-mesenchymal transition through RAS signaling pathway and therapeutic implications in human cancer

RAS effector signaling instead of being simple, unidirectional and linear cascade, is actually recognized as highly complex and dynamic signaling network. RAF-MEK-ERK cascade, being at the center of complex signaling network, links to multiple scaffold proteins through feed forward and feedback mechanisms and dynamically regulate tumor initiation and progression. Three isoforms of Ras harbor mutations in a cell and tissue specific manner. Besides mutations, their epigenetic silencing also attributes them to exhibit oncogenic activities. Recent evidences support the functions of RAS oncoproteins in the acquisition of tumor cells with Epithelial-to-mesenchymal transition (EMT) features/ epithelial plasticity, enhanced metastatic potential and poor patient survival. Google Scholar electronic databases and PubMed were searched for original papers and reviews available till date to collect information on stimulation of EMT core inducers in a Ras driven cancer and their regulation in metastatic spread. Improved understanding of the mechanistic basis of regulatory interactions of microRNAs (miRs) and EMT by reprogramming the expression of targets in Ras activated cancer, may help in designing effective anticancer therapies. Apparent lack of adverse events associated with the delivery of miRs and tissue response make 'drug target miRNA' an ideal therapeutic tool to achieve progression free clinical response.

Identification of potential crucial genes associated with carcinogenesis of clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is a common genitourinary malignancy with high mortality. However, the molecular pathogenesis of ccRCC remains unclear and effective biomarkers for daily practice are still limited. Thus, we aimed to identify the potential crucial genes and pathways associated with carcinogenesis of ccRCC and further analyze the molecular mechanisms implicated in tumorigenesis. In the present study, expression profiles GSE 66270, GSE 53757, GSE 36895, and GSE 76351 were downloaded from GEO database, including 244 matched primary and adjacent normal tissues, furthermore, the level 3 RNAseq dataset (RNAseqV2 RSEM) of KIRC was also downloaded from The Cancer Genome Atlas (TCGA), which consist of 529 ccRCC tumors and 72 normal tissues. Then, differentially expressed genes (DEGs) and pathway enrichment were analyzed by using R software. A total of 129 up- and 123 down-regulated genes were identified, which were aberrantly expressed both in GEO and TCGA data. Second, Gene ontology (GO) analyses revealed that most of the DEGs were significantly enriched in integral component of membrane, extracellular exosome, plasma membrane, cell adhesion, and receptor binding. Signaling pathway analyses indicated that DEGs had common pathways in signal transduction, metabolism, and immune system. Third, hub genes were identified with protein-protein interaction (PPI) network, including PTPRC, TGFB1, EGF, MYC, ITGB2, CTSS, FN1, CCL5, KNG1, and CD86. Additionally, sub-networks analyse was also performed by using MCODE plugin. In conclusion, the novel DEGs and pathways in ccRCC identified in this study may provide new insight into the underlying molecular mechanisms that facilitates RCC carcinogenesis.

CCNA2 facilitates epithelial-to-mesenchymal transition via the integrin αvβ3 signaling in NSCLC

Non-small cell lung carcinoma (NSCLC) is the most common malignancy with the highest morbidity and mortality. Studies have demonstrated that the abnormal expression of cyclin-A2 (CCNA2) is associated with multiple malignancies, yet its functional role in NSCLC metastasis remains to be elucidated. In the present study, we investigated the role of CCNA2 in regulating migration and invasion of NSCLC cells by establishing NSCLC cell strains with constitutively silenced or elevated CCNA2 expression. We demonstrated that ectopic expression of CCNA2 accelerates NSCLC cells migration and invasion in vitro through cell wound scratching and Transwell invasion assays. Conversely, further analysis indicated that suppression of CCNA2 expression via siRNA inhibits metastasis of NSCLC cells. In addition, we studied the correlation between CCNA2 expression and overall survival using the Kaplan-Meier Plotter database in NSCLC cancers. There was correlation between CCNA2 expression levels and patient survival. Finally, our findings demonstrate that CCNA2 promotes invasion and migration of NSCLC cells through integrin αVβ3 signaling pathway. Collectively, this study provides novel insights into that CCNA2 represents a crucial regulator of NSCLC cells metastasis and suggests targeted treatment of CCNA2-expressing cancer serves as a new therapeutic target for NSCLC.