Cortactin and Exo70 mediated invasion of hepatoma carcinoma cells by MMP-9 secretion

The mechanism of USP43 in the development of tumor: a literature review

Ubiquitination of the proteins is crucial for governing protein degradation and regulating fundamental cellular processes. Deubiquitinases (DUBs) have emerged as significant regulators of multiple pathways associated with cancer and other diseases, owing to their capacity to remove ubiquitin from target substrates and modulate signaling. Consequently, they represent potential therapeutic targets for cancer and other life-threatening conditions. USP43 belongs to the DUBs family involved in cancer development and progression. This review aims to provide a comprehensive overview of the existing scientific evidence implicating USP43 in cancer development. Additionally, it will investigate potential small-molecule inhibitors that target DUBs that may have the capability to function as anti-cancer medicines.

Cav2.2-NFAT2-USP43 axis promotes invadopodia formation and breast cancer metastasis through cortactin stabilization

Distant metastasis is the main cause of mortality in breast cancer patients. Using the breast cancer genomic data from The Cancer Genome Atlas (TCGA), we identified brain specific Ca_v2.2 as a critical regulator of metastasis. Ca_v2.2 expression is significantly upregulated in breast cancer and its higher expression is inversely correlated with survival suggesting a previously unappreciated role of Ca_v2.2 in breast cancer. Ca_v2.2 is required for breast cancer migration, invasion, and metastasis. Interestingly, Ca_v2.2 promotes invadopodia formation and extracellular matrix (ECM) degradation through the stabilization of invadopodia component cortactin in a proteosome-dependent manner. Moreover, deubiquitinating enzyme USP43 mediated the functions of Ca_v2.2 in cortactin stabilization, invadopodia formation, ECM degradation, and metastasis. Interestingly, Ca_v2.2 upregulates USP43 expression through NFAT2 dephosphorylation and nuclear localization. Our study uncovered a novel pathway that regulates cortactin expression and invadopodia formation in breast cancer metastasis.

Cortactin Expression is a Novel Biomarker for Risk Stratification of T-Cell Acute Lymphoblastic Leukemia

The role of cortactin in T-cell acute lymphoblastic leukemia (T-ALL) tissue infiltration has been previously reported. However, its impact on patients' responsiveness to therapy and patient's outcome was not previously addressed. This study was conducted on 60 T-ALL pediatric patients at diagnosis and 10 nonleukemic controls. Cortactin and HS1 expressions were identified by real-time polymerase chain reaction. Cortactin and HS1 expression were significantly higher in T-All patients as compared with controls as well as postinduction levels (P≤0.001 for both). The high cortactin expression was significantly associated with high peripheral white cell counts (P≤0.001), blood blast cells (P≤0.001) and central nervous system (CNS) infiltration (P≤0.001), and early precursor T-ALL subtype (P≤0.001) as compared with the remaining groups. The induction of remission response was significantly higher in T-ALL patients with lower cortactin expression levels as compared with T-ALL patients with higher one (P≤0.001). The high cortactin and HS1 expressions were significantly predictors of CNS infiltrations (hazard ratios [HR]: 1.051, confidence interval [CI]: 1.02-1.13, P=0.04 and HR: 1.87, CI: 1.23-2.091, P=0.002, respectively) and bone marrow relapse (HR: 1.43, CI: 1.18-1.92, P=0.004 and HR: 1.07, CI: 1.01-1.24, P=0.002, respectively). Furthermore, high cortactin expression levels were associated with shorter B-ALL patients' overall survival as compared with those with lower cortactin levels (P=0.002). In conclusion, high expression of cortactin and/or HS1 at diagnosis is a bad prognostic marker of T-ALL patients' outcome. Moreover, cortactin and/or HS1 expression could be used as a biomarker for refining risk stratification of T-ALL.

Deregulation of Exo70 Facilitates Innate and Acquired Cisplatin Resistance in Epithelial Ovarian Cancer by Promoting Cisplatin Efflux

Simple Summary

Innate and acquired platinum resistance are the leading causes of epithelial ovarian cancer (EOC) mortality. However, the mechanisms remain elusive. Here we found that Exo70, a key subunit of the exocyst, is upregulated in EOC and promotes cisplatin efflux to facilitate innate resistance. More interestingly, cisplatin could downregulate Exo70 to sustain cell sensitivity. However, this function was hampered during prolonged cisplatin treatment, which in turn stabilized Exo70 to facilitate the acquired cisplatin resistance of EOC cells. Our study potentiates Exo70 as a promising target to overcome cisplatin resistance in EOC.

Abstract

Whilst researches elucidating a diversity of intracellular mechanisms, platinum-resistant epithelial ovarian cancer (EOC) remains a major challenge in the treatment of ovarian cancer. Here we report that Exo70, a key subunit of the exocyst complex, contributes to both innate and acquired cisplatin resistance of EOC. Upregulation of Exo70 is observed in EOC tissues and is related to platinum resistance and progression-free survival of EOC patients. Exo70 suppressed the cisplatin sensitivity of EOC cells through promoting exocytosis-mediated efflux of cisplatin. Moreover, cisplatin-induced autophagy-lysosomal degradation of Exo70 protein by modulating phosphorylation of AMPK and mTOR, thereby reducing the cellular resistance. However, the function was hampered during prolonged cisplatin treatment, which in turn stabilized Exo70 to facilitate the acquired cisplatin resistance of EOC cells. Knockdown of Exo70, or inhibiting exocytosis by Exo70 inhibitor Endosidin2, reversed the cisplatin resistance of EOC cells both in vitro and in vivo. Our results suggest that Exo70 overexpression and excessive stability contribute to innate and acquired cisplatin resistance through the increase in cisplatin efflux, and targeting Exo70 might be an approach to overcome cisplatin resistance in EOC treatment.

Identification of potential biomarkers of peripheral blood mononuclear cell in hepatocellular carcinoma using bioinformatic analysis: A protocol for systematic review and meta-analysis

BACKGROUND

Hepatocellular carcinoma (HCC) is the cause of an overwhelming number of cancer-related deaths across the world. Developing precise and noninvasive biomarkers is critical for diagnosing HCC. Our research was designed to explore potentially useful biomarkers of host peripheral blood mononuclear cell (PBMC) in HCC by integrating comprehensive bioinformatic analysis.

METHODS

Gene expression data of PBMC in both healthy individuals and patients with HCC were extracted from the Gene Expression Omnibus (GEO) to identify differentially expressed genes (DEGs). The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were applied to annotate the function of DEGs. Protein-protein interaction analysis was performed to screen the hub genes from DEGs. cBioportal database analysis was performed to assess the prognostic significance of hub genes. The Cancer Cell Line Encyclopedia (CCLE) and The Human Protein Atlas (HPA) database analyses were performed to confirm the expression levels of the hub genes in HCC cells and tissue.

RESULTS

A total of 95 DEGs were screened. Results of the GO analysis revealed that DEGs were primarily involved in platelet degranulation, cytoplasm, and protein binding. Results of the KEGG analysis indicated that DEGs were primarily enriched in focal adhesion. Five genes, namely, myosin light chain kinase (MYLK), interleukin 1 beta (IL1B), phospholipase D1 (PLD1), cortactin (CTTN), and moesin (MSN), were identified as hub genes. A search in the CCLE and HPA database showed that the expression levels of these hub genes were remarkably increased in the HCC samples. Survival analysis revealed that the overexpression of MYLK, IL1B, and PLD1 may have a significant effect on HCC survival. The aberrant high expression levels of MYLK, IL1B, and PLD1 strongly indicated worse prognosis in patients with HCC.

CONCLUSIONS

The identified hub genes may be closely linked with HCC tumorigenicity and may act as potentially useful biomarkers for the prognostic prediction of HCC in PBMC samples.

Actin regulators in cancer progression and metastases: From structure and function to cytoskeletal dynamics

The cytoskeleton is a central factor contributing to various hallmarks of cancer. In recent years, there has been increasing evidence demonstrating the involvement of actin regulatory proteins in malignancy, and their dysregulation was shown to predict poor clinical prognosis. Although enhanced cytoskeletal activity is often associated with cancer progression, the expression of several inducers of actin polymerization is remarkably reduced in certain malignancies, and it is not completely clear how these changes promote tumorigenesis and metastases. The complexities involved in cytoskeletal induction of cancer progression therefore pose considerable difficulties for therapeutic intervention; it is not always clear which cytoskeletal regulator should be targeted in order to impede cancer progression, and whether this targeting may inadvertently enhance alternative invasive pathways which can aggravate tumor growth. The entire constellation of cytoskeletal machineries in eukaryotic cells are numerous and complex; the system is comprised of and regulated by hundreds of proteins, which could not be covered in a single review. Therefore, we will focus here on the actin cytoskeleton, which encompasses the biological machinery behind most of the key cellular functions altered in cancer, with specific emphasis on actin nucleating factors and nucleation-promoting factors. Finally, we discuss current therapeutic strategies for cancer which aim to target the cytoskeleton.

XPD inhibits cell growth and invasion and enhances chemosensitivity in esophageal squamous cell carcinoma by regulating the PI3K/AKT signaling pathway

Esophageal squamous cell carcinoma (ESCC) is a lethal disease due to its high aggressiveness. The aim of the present study was to investigate the role of xeroderma pigmentosum complementation group D (XPD) in the growth and invasion of ESCC and to elucidate the potential underlying molecular mechanisms. Western blot analysis and RT-qPCR were used to detect the expression level of XPD in ESCC tissue samples and adjacent normal esophageal tissue samples. The pEGFP-N2/XPD plasmid was transfected into human ESCC cell lines (EC9706 and EC109). The proliferation, apoptosis, migration and invasion of EC9706 or EC109 cells were assessed following transfection with the XPD overexpression plasmid. The chemosensitivity of EC9706 or EC109 cells to cisplatin or fluorouracil was evaluated by CCK-8 assay. The expression levels of phosphoinositide 3-kinase (PI3K)/AKT, nuclear factor (NF)-κB, Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) and mitogen-activated protein kinase (MAPK) signaling pathway-related genes were detected by RT-qPCR and western blot analysis. The results demonstrated that the expression level of XPD was markedly lower in ESCC tissue samples than in adjacent normal esophageal tissue samples. The pEGFP-N2/XPD plasmid was successfully transfected into EC9706 or EC109 cells, inducing XPD overexpression. A High XPD expression markedly suppressed cell proliferation, migration and invasion, and increased the apoptotic rate of EC9706 and EC109 cells. Furthermore, the overexpression of XPD significantly increased the chemosensitivity of EC9706 and EC109 cells to cisplatin or fluorouracil. Following XPD overexpression, the expression levels of PI3K, p-AKT, c-Myc, Cyclin D1, Bcl-2, vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP)-9 were markedly downregulated, while the expression level of p21 was markedly upregulated. On the whole, the findings of the present study demonstrate that XPD inhibits the growth and invasion of EC9706 and EC109 cells, whilst also enhancing the chemosensitivity of EC9706 and EC109 cells to cisplatin or fluorouracil by regulating the PI3K/AKT signaling pathway. XPD may thus be an underlying target for ESCC treatment and drug resistance.

Shear stress-induced endothelial adrenomedullin signaling regulates vascular tone and blood pressure

Hypertension is a primary risk factor for cardiovascular diseases including myocardial infarction and stroke. Major determinants of blood pressure are vasodilatory factors such as nitric oxide (NO) released from the endothelium under the influence of fluid shear stress exerted by the flowing blood. Several endothelial signaling processes mediating fluid shear stress-induced formation and release of vasodilatory factors have been described. It is, however, still poorly understood how fluid shear stress induces these endothelial responses. Here we show that the endothelial mechanosensitive cation channel PIEZO1 mediated fluid shear stress-induced release of adrenomedullin, which in turn activated its Gs-coupled receptor. The subsequent increase in cAMP levels promoted the phosphorylation of endothelial NO synthase (eNOS) at serine 633 through protein kinase A (PKA), leading to the activation of the enzyme. This Gs/PKA-mediated pathway synergized with the AKT-mediated pathways leading to eNOS phosphorylation at serine 1177. Mice with endothelium-specific deficiency of adrenomedullin, the adrenomedullin receptor, or Gαs showed reduced flow-induced eNOS activation and vasodilation and developed hypertension. Our data identify fluid shear stress-induced PIEZO1 activation as a central regulator of endothelial adrenomedullin release and establish the adrenomedullin receptor and subsequent Gs-mediated formation of cAMP as a critical endothelial mechanosignaling pathway regulating basal endothelial NO formation, vascular tone, and blood pressure.

Cortactin in cancer cell migration and invasion

Cortactin, a substrate of sarcoma (Src) kinases, is an actin-binding protein that is involved in cytoskeletal regulation, and is frequently overexpressed in cancer cells. Binding to the actin related protein 2/3 (Arp2/3) complex stimulates cortactin activity, which promotes F-actin nucleation and assembly. Cortactin promotes cancer cell migration and invasion, and plays a pivotal role in invadopodia formation and extra cellular matrix degradation. Overexpression of cortactin, by amplification of the chromosomal band 11q13, increases tumor aggressiveness. In this review, we report on the current knowledge and potential mechanisms of action of cortactin as a critical mediator of cancer cell migration and invasion.

Exo70 is an independent prognostic factor in colon cancer

Exo70, a key component of the Exocyst complex, plays important roles in human cancer progression beyond exocytosis. However, the expression of Exo70 and its prognostic value for patients with colon cancer has not been well investigated to date. In this study, we observed that the mRNA and protein levels of Exo70 were upregulated in 11 of 13 colon cancer tissues, compared with their normal counterparts, which was validated by immunohistochemical analysis in a tissue microarray containing 89 pairs of colon cancer tissues and the matched adjacent normal tissues. Statistical analysis revealed that Exo70 expression is positively correlated with tumor size, invasion depth, TNM stage and distant metastasis. Kaplan-Meier survival analysis showed that colon cancer patients with higher Exo70 expression have a poorer clinical outcome than those with lower Exo70 expression. Multivariate Cox regression analysis revealed that Exo70, age and distant metastasis were there independent prognostic factors for overall survival rate of colon cancer patients. Through gain- and loss of Exo70 in colon cancer cells, we found that Exo70 could enhance the migration ability of colon cancer cells. Taken together, our studies revealed that Exo70 might be a promising negative prognostic factor and a potential therapeutic target for colon cancer.

Tumor LXR Expression is a Prognostic Marker for Patients with Hepatocellular Carcinoma

Liver X receptor (LXR) activation exerts an anti-tumor effect. However, whether the tumor LXR expression has prognostic significance in hepatocellular carcinoma (HCC) patient has not been addressed yet. Primary HCC and the adjacent non-tumor tissues were obtained from 169 patients who underwent routine curative surgical treatment. All patients were followed for prognosis analyses. Tumor LXR was detected by immunohistochemical analysis. In in vitro study, several HCC cell lines were cultured for cellular protein detection of LXR and other cytokines, including nuclear factor kappa (NFκB), Matrix metalloproteinases 2 and 9 (MMP-2 and -9). Meanwhile, the invasion ability of cultured HCC cell lines was performed. We found that LXR expression status in tumor samples is associated with the clinical characteristics, such as tumor stage and metastasis, of HCC patients. Prognosis analysis shows that tumor LXR expression status is closely related to the post-operative outcome in HCC patients who underwent surgical treatment. Patients with low LXR expression have a significantly lower mean 5-year overall survival rate and mean overall survival period than those with high LXR level. Our in vitro data reveal that HCC cell lines had increased NF-κB, MMP2, MMP9 and invasive ability than normal cell line, which are suppressed by LXR activation via NFκB pathway. Our data suggest that LXR could be used as a biomarker for HCC prognosis. Further study is warranted to explore the molecular mechanism under which LXR regulates tumor behaves.