K-Ras-ERK1/2 accelerates lung cancer cell development via mediating H3K18ac through the MDM2-GCN5-SIRT7 axis

Emerging role of GCN5 in human diseases and its therapeutic potential

As the first histone acetyltransferase to be cloned and identified in yeast, general control non-depressible 5 (GCN5) plays a crucial role in epigenetic and chromatin modifications. It has been extensively studied for its essential role in regulating and causing various diseases. There is mounting evidence to suggest that GCN5 plays an emerging role in human diseases and its therapeutic potential is promising. In this paper, we begin by providing an introduction GCN5 including its structure, catalytic mechanism, and regulation, followed by a review of the current research progress on the role of GCN5 in regulating various diseases, such as cancer, diabetes, osteoporosis. Thus, we delve into the various aspects of GCN5 inhibitors, including their types, characteristics, means of discovery, activities, and limitations from a medicinal chemistry perspective. Our analysis highlights the importance of identifying and creating inhibitors that are both highly selective and effective inhibitors, for the future development of novel therapeutic agents aimed at treating GCN5-related diseases.

Testis-specific protein Y-encoded 1 regulates androgen receptor expression through the MAPK/ERK pathway in male hepatocellular carcinoma

OBJECTIVES

To analyze the mechanism of testis-specific protein Y-encoded 1 (TSPY1) in male hepatocellular carcinoma (HCC).

METHODS

This experimental study was carried out at Guangxi Medical University's First Affiliated Hospital, Guangxi, China, between January 2016 and December 2019. The expression of TSPY1, androgen receptor (AR), messenger ribonucleic acids (mRNAs), and proteins were detected by qRT-PCR and Western blotting. The co-localization and interaction of TSPY1 and AR were observed by immunofluorescence assay and co-immunoprecipitation. Hepatocellular carcinoma cells overexpressing and silencing TSPY1 were constructed, and the expression and phosphorylation levels of TSPY1, AR, and mitogen-activated protein kinases/extracellular signal-regulated kinases (MAPK/ERK) signaling pathway-related key molecules ERK1/2, p38, and JNK were also detected.

RESULTS

The expression levels of TSPY1, AR mRNAs, and proteins were highly positively correlated in HCC cells in different metastatic potentials with a high correlation coefficient of R=0.929 and R=0.884. Testis-specific protein Y-encoded 1 and AR were then co-localized in the nucleus of HCC cells, and TSPY1 and AR can interact with each other. In addition, the expression of AR and phosphorylation of ERK1/2 were enhanced in TSPY1 overexpressed Huh7 cells. They were reduced in HCCLM3 cells with TSPY1 knockdown expression. In addition, in response to blocking MAPK/ERK signaling activity, AR was reduced in expression.

CONCLUSION

These findings suggested that there was a positive correlation between TSPY1 expression and AR in male HCC cells, and high TSPY1 expression stimulates AR expression, MAPK/ERK signaling pathway may be involved in its mechanism.

Roles of sirtuins in asthma

Sirtuins are nicotinamide adenine dinucleotide (NAD⁺)-dependent lysine deacylases and deacetylases that participate in a variety of cellular processes, including transcriptional activity, energy metabolism, DNA damage response, inflammation, apoptosis, autophagy, and oxidative stress. As a result, sirtuins are linked to multiple pathophysiological processes, such as cardiovascular diseases, metabolic diseases, autoimmune diseases, infectious diseases, and respiratory diseases. Asthma is the most common respiratory disease, which is characterized by airway inflammation and airway remodeling. Accumulating evidence has indicated that sirtuins are involved in the pathogenesis of asthma. Furthermore, some studies have suggested that sirtuin modulators are potential agents for the treatment of asthma via alteration of the expression or activity of sirtuins. In this review, we illustrate the role of sirtuins in asthma, discuss related molecular mechanisms, and evaluate the sirtuins-targeted therapy for asthma.

COL8A1 Promotes NSCLC Progression Through IFIT1/IFIT3-Mediated EGFR Activation

Activation of EGFR is a major risk factor for non-small cell lung cancer (NSCLC). Understanding the molecular events promoting EGFR activation can help us gain more insights into the progression of NSCLC. In this study, we demonstrate that collagen type VIII alpha 1 chain (COL8A1), an extracellular matrix component, was overexpressed in NSCLC. In NSCLC cells, knockdown of COL8A1 suppressed cell growth, cycle progression, and migration, and induced cell apoptosis. While COL8A1 overexpression promoted cell proliferation and inhibited cell apoptosis. In addition, we found that COL8A1 depletion reduced interferon response signaling and downregulated (IFIT1) and interferon-induced proteins with tetratricopeptide repeats 3 (IFIT3). Moreover, we indicated that COL8A1 could upregulate IFIT1 and IFIT3 mediated EGFR activation in vitro and in vivo. Lastly, there was a positive correlation among COL8A1, IFIT1, and IFIT3 expression, and EGFR activity in patients with NSCLC. Overall, our data demonstrate that COL8A1 contributes to NSCLC proliferation and invasion through EGFR activation, dependent on IFIT1 and IFIT3 expression.

Discovery of SIRT7 Inhibitor as New Therapeutic Options Against Liver Cancer

Optimal therapeutic strategies for liver cancer patients remain challenging due to the high recurrence rate after surgical resection and chemotherapy resistance. Emerging evidence has shown that epigenetic factor SIRT7 is involved in various aspects of cancer biology, while inactive SIRT7 reverses human cancer phenotype and suppresses tumor growth. In the present study, we predicted the SIRT7 structure by using the fold recognition (or threading) method and performed structure-based virtual screening to develop specific SIRT7 inhibitor by docking 939319 structurally diverse compounds with SIRT proteins. Compounds with high affinities to SIRT7 but low affinities to other SIRT proteins were chosen as candidates of specific SIRT7 inhibitor. Our leading compounds 2800Z and 40569Z showed strong interaction with SIRT7 protein, and specifically inhibited SIRT7 deacetylation activity in vitro. Our docking results also revealed that ARG-120, TRP-126, and HIS-187 were critical sites responsible for interaction of SIRT7 with small molecules. Mutations in the aforementioned sites significantly abolished interaction and inhibitory effects of compounds to SIRT7. In addition, in vivo data indicated that compounds 2800Z and 40569Z were able to induce apoptosis and increase chemosensitivity to sorafenib in human liver cancer. Our findings demonstrated targeting SIRT7 may offer novel therapeutic options for cancer management, and the value of compounds 2800Z and 40569Z as chemical probes for the study of SIRT7 biological functions as well as starting leads for the development of new therapeutic options against liver cancer.

Role of ZEB family members in proliferation, metastasis and chemoresistance of prostate cancer cells: Revealing signaling networks

Prostate cancer (PCa) is one of the leading causes of death worldwide. A variety of strategies including surgery, chemotherapy, radiotherapy and immunotherapy are applied for PCa treatment. PCa cells are responsive towards therapy at early stages, but they can obtain resistance in the advanced stage. Furthermore, their migratory ability is high in advanced stages. It seems that genetic and epigenetic factors play an important in this case. Zinc finger E-box-binding homeobox (ZEB) is a family of transcription with two key members including ZEB1 and ZEB2. ZEB family members are known due to their involvement in promoting cancer metastasis via EMT induction. Recent studies have shown their role in cancer proliferation and inducing therapy resistance. In the current review, we focus on revealing role of ZEB1 and ZEB2 in PCa. ZEB family members that are able to significantly promote proliferation and viability of cancer cells. ZEB1 and ZEB2 enhance migration and invasion of PCa cells via EMT induction. Overexpression of ZEB1 and ZEB2 is associated with poor prognosis of PCa. ZEB1 and ZEB2 upregulation occurs during PCa progression and can provide therapy resistance to cancer cells. PRMT1, Smad2, and non-coding RNAs can function as upstream mediators of the ZEB family. Besides, Bax, Bcl-2, MRP1, N-cadherin and E-cadherin can be considered as downstream targets of ZEB family in PCa.