ERas regulates cell proliferation and epithelial-mesenchymal transition by affecting Erk/Akt signaling pathway in pancreatic cancer

CBLC promotes the development of colorectal cancer by promoting ABI1 degradation to activate the ERK signaling pathway

CBLC (CBL proto-oncogene C) is an E3 ubiquitin protein ligase that plays a key role in cancers. However, the function and mechanism of CBLC in colorectal cancer (CRC) has not been fully elucidated. The aim of this study was to investigate the function of CBLC in CRC and its underlying molecular mechanism. High CBLC levels were certified in tumor tissues of CRC patients, and its expression was positively associated with TNM stage. Next, we explored the role of CBLC in CRC using gain or loss of function. For biological function analysis, CCK-8 cell proliferation, colony formation, flow cytometry, scratch, and transwell assays collectively suggested that CBLC overexpression promoted cell proliferation, cell cycle progression, migration and invasion. As observed, CBLC knockdown exhibited exactly opposite effects, resulting in impaired tumorigenicity in vitro. Xenograft studies displayed that CBLC overexpression accelerated tumor growth and promoted tumor metastasis to the lung, while the inhibitory effects of CBLC knockdown on tumorigenicity and metastasis ability of CRC cells was also confirmed. Furthermore, the molecular mechanism of CBLC in CRC was explored. CBLC induced the activation of ERK signaling pathway, further leading to its pro-tumor role. Notably, CBLC decreased ABI1 (Abelson interactor protein-1, a candidate tumor suppressor) protein levels through its ubiquitin ligase activity, while ABI1 upregulation abolished the effects of CBLC on the tumorigenesis of CRC. Taken together, these results demonstrate that CBLC acts as a tumor promoter in CRC through triggering the ubiquitination and degradation of ABI1 and activating the ERK signaling pathway. CBLC may be a potential novel target for CRC.

ERAS Is Constitutively Expressed in the Tissues of Adult Horses and May Be a Key Player in Basal Autophagy

ERas is a new gene of the Ras family found in murine embryonic stem (ES) cells. Its human ortholog is not expressed in human ES cells. So far ERas gene has only been found to be expressed in the tissues of adult cynomolgus monkeys and cattle; however, information about ERAS expression or its potential functions in equine tissues is lacking. This study was performed to investigate whether Eras is an equine functional gene and whether ERAS is expressed in the tissues of adult horses and determine its potential physiological role. Expression of the ERas gene was detected in all examined adult tissues, and the RT-PCR assay revealed ERAS transcripts. Protein expression was also detected by Western blot analysis. Quantitative real time RT-qPCR analysis revealed that different expression levels of ERAS transcripts were most highly expressed in the testis. Immunohistochemically, ERAS was found to be localized prevalently in the plasmatic membrane as well as cytoplasm of the cells. ERAS was a physical partner of activated PDGFβR leading to the AKT signaling. ERAS was found to interact with a network of proteins (BAG3, CHIP, Hsc70/Hsp70, HspB8, Synpo2, and p62) known to play a role in the chaperone-assisted selective autophagy (CASA), which is also known as BAG3-mediated selective macroautophagy, an adaptive mechanism to maintain cellular homeostasis. Furthermore, ERAS was found to interact with parkin. PINK1, BNIP3, laforin. All these proteins are known to play a role in parkin-dependent and -independent mitophagy. This is the first study demonstrating that Eras is a functional gene, and that ERAS is constitutively expressed in the tissues of adult horses. ERAS appears to play a physiological role in cellular proteostasis maintenance, thus mitigating the proteotoxicity of accumulated misfolded proteins and contributing to protection against disease. Finally, it is conceivable that activation of AKT pathway by PDGFRs promotes actin reorganization, directed cell movements, stimulation of cell growth.

MK8722, an AMPK activator, inhibiting carcinoma proliferation, invasion and migration in human pancreatic cancer cells

BACKGROUND

MK8722 is a potent and systemic pan-AMPK activator. It is an effective, direct, allosteric activator of AMPK complex in many mammals. This study tried to explore the underlying anti-cancer molecular mechanism of MK8722 in human pancreatic cancer cells (PCCs).

METHODS

The anti-proliferation, invasion and migration functions of MK8722 in human pancreatic cancer analyzed by real time cellular analysis, colony formation assay, cell migration assay, transwell assay and flow cytometery analysis. Moreover, the potential targeted signaling pathway was tested via RNA-seq and pathway enrichment analysis.

RESULTS

In the present study, we investigated the anti-PCCs effects of MK8722 on two different human pancreatic cancer cell lines (PANC-1 and Patu8988). The results showed that MK8722 significantly inhibited human tumor cells proliferation and migration/invasion in a dose-dependent manner. Additionally, the influence of MK8722 was examined by analyzing the expression of potential key genes and pathways, which may provide novel insights to the mechanism of MK8722.

CONCLUSION

The inhibition of pancreatic cancer by MK8722 through a number of pathways that inhibit carcinoma proliferation, invasion and migration. The potential effect of MK8722 might be determined by regulating the expression of AL162151, IER2, REPIN1, KRT80 to inhibit cycle arrest and migration.

ERAS, a Member of the Ras Superfamily, Acts as an Oncoprotein in the Mammary Gland

Simple Summary

The genes of the RAS family are among the group of genes most frequently mutated in human cancer. ERAS is a relatively unknown gene of this family. Although ERAS is overexpressed in some tumoral samples and in several cancer cell lines of human origin, it is not known if its expression drives tumor formation or if, alternatively, its expression is a secondary event in tumoral transformation. In this report, in order to clarify the role of ERAS in mammary tumorigenesis, we studied transgenic mice expressing ERAS in myoepithelial cells of mammary and other exocrine glands and in basal cells of stratified epithelia. These mice displayed an altered development and function of the mammary glands, and suffered high-frequency tumoral lesions in the mammary glands resembling a rare human breast tumor named malignant adenomyoepithelioma. Our results clearly demonstrate that ERAS is a true oncogene able to produce mammary tumors when inappropriately expressed.

Abstract

ERAS is a relatively uncharacterized gene of the Ras superfamily. It is expressed in ES cells and in the first stages of embryonic development; later on, it is silenced in the majority of cell types and tissues. Although there are several reports showing ERAS expression in tumoral cell lines and human tumor samples, it is unknown if ERAS deregulated expression is enough to drive tumor development. In this report, we have generated transgenic mice expressing ERAS in myoepithelial basal cells of the mammary gland and in basal cells of stratified epithelia. In spite of the low level of ERAS expression, these transgenic mice showed phenotypic alterations resembling overgrowth syndromes caused by the activation of the AKT-PI3K pathway. In addition, their mammary glands present developmental and functional disabilities accompanied by morphological and biochemical alterations in the myoepithelial cells. These mice suffer from tumoral transformation in the mammary glands with high incidence. These mammary tumors resemble, both histologically and by the expression of differentiation markers, malignant adenomyoepitheliomas. In sum, our results highlight the importance of ERAS silencing in adult tissues and define a truly oncogenic role for ERAS in mammary gland cells when inappropriately expressed.