ACTL6A expression promotes invasion, metastasis and epithelial mesenchymal transition of colon cancer

Pan-cancer analysis reveals BAF complexes as immune-related biomarkers and validation in triple-negative breast cancer

AIMS

BAF complexes (BAFs), ATP-dependent regulators of chromatin structure, play a significant role in cancer progression. This pan-cancer study aimed to decode the potential of specific BAFs in the pathology, immunity, and therapy of targeted cancers.

MATERIALS AND METHODS

Data were retrieved from The Cancer Genome Atlas, Gene Expression Omnibus, and IMvigor210 databases and were analyzed for expression patterns, prognostic value, mutational signatures, biological pathways, tumor immune microenvironment (TIME) remodeling, and therapeutic resistance of BAFs. Experimental validation was also conducted.

KEY FINDINGS

BAFs exhibit abnormal expression in various human cancers. The BAFs model and nomogram (based on multiple variables) were developed as prognostic tools. BAFs regulate the TIME and influence the response to anti-PD-L1 therapy, particularly through ACTL6A, as observed in RNA sequencing and single-cell RNA sequencing datasets (high-resolution gene expression data at the single-cell level). ACTLA6 is a major adverse gene in the prognostic model. Patients with high ACTL6A expression showed significantly worse overall survival (hazard ratio = 1.32, 95 % CI: 1.26-1.39, p < 0.001). ACTL6A expression escalates with breast cancer (BRCA) malignancy, particularly in triple-negative BRCA (TNBC), and correlates with immune checkpoint expression while playing a crucial role in promoting cancer metastasis in TNBC.

SIGNIFICANCE

Our findings first emphasize the significance of a novel BAFs model for patient prognosis and corroborate the considerable role of BAFs as immune-related biomarkers in pan-cancer progression. ACTL6A has a dual role as an immune-related biomarker and potential therapeutic target in TNBC, deepening our comprehension of its function as an oncogene.

Integrated single-nuclear RNA sequencing analysis reveals distinct characteristics of mucinous adenocarcinoma in right-sided colon cancer

Mucinous adenocarcinoma (MAC) is a unique histological subtype of colorectal cancer (CRC), which usually occurs in the right-sided colon with poor prognosis. Our previous studies reveled unique clinicopathological characteristic of MAC, but the distinct molecular features and tumor microenvironment (TME) characteristics remain clarify systematically. In this study, we conducted a single nuclear RNA sequencing (snRNA-seq) analysis for CRC tissues with different histological subtypes, including MAC, partial mucinous adenocarcinoma (pMAC) and non-specific adenocarcinoma (AC). Our results show that MAC has a unique transcriptome profile and a distinct single-cell characteristic. It exhibited a higher degree of tumor purity but a lower composition of TME. MAC had a distinct cell-cell communication microenvironment and a particular evolutionary trajectory. The EpithelialCells of MAC closely interacted with fibroblasts, endothelial cells, and mural cells clusters. Furthermore, molecular functional characteristics analysis revealed that MAC enriched EpithelialCells, Fibroblasts, and Endothelial cells clusters have a high active in glycolysis, inflammation, and angiogenesis respectively. This comprehensive study first demonstrated that MAC is a unique histological subtype of right-sided CRC in the single cell level, and elucidated its tumor microenvironment composition and biological function characteristics, which will help us better understand the intrinsic feature of MAC.

Unveiling the role of ACTL6A in uveal melanoma metastasis and immune microenvironment

PURPOSE

To predict and evaluate the possible mechanisms and clinical value of ACTL6A in the prognosis and development of UM.

METHODS

Bioinformatics analyze the relationship between ACTL6A and immunity in UM, which derived from TCGA, Gene Expression Omnibus (GEO) databases. Tumor-infltrated immune cells were demonstrated using QUANTISEQ and MCP-counter. Furthermore, scRNA-seq was used to detect ACTL6A expression, distribution, immune infiltration and revealing the gene expression profile of UM.

RESULTS

The expression of ACTL6A was lower in UM compared with pantumor in TCGA databases. Kaplan-Meier analysis revealed that downregulated ACTL6A was associated with poor OS, and ACTL6A was associated with cancer stem cells (CSCs) and immune infiltration. Moreover, ACTL6A might act as a chemotherapy resistance gene and closely relate- to epithelial-mesenchymal transition. Analysis in 8 GSE databases showed that IL13, TPTE, IL17B and CCL22 genes were significantly overexpressed in metastatic UM. Furthermore, the single-cell transcriptomic profling identified a new cell cluster - as a unique type of immune cell, which associating with malignant cell heterogeneity and complexity, and further revealing that the metastasis of UM is mainly associated with CD4 Tconv, B , CD8 Tex, and Plasma cells.

CONCLUSIONS

Downregulated ACTL6A acts as a risk factor for poor prognosis in UM, which implies as an potential prognostic marker for independent targeted immunotherapy.

Actl6a regulates autophagy via Sox2-dependent Atg5 and Atg7 expression to inhibit apoptosis in spinal cord injury

INTRODUCTION

Spinal cord injury (SCI) is a severe central nervous system disorder with limited treatment options. While autophagy plays a protective role in neural repair, its regulatory mechanisms in SCI remain unclear. Actin-like protein 6A (Actl6a) influences cell fate and neural development, yet its specific role in SCI repair is not well understood. This study investigates Actl6a's function in regulating autophagy and apoptosis via the transcription factor Sox2 in SCI.

OBJECTIVES

This study aims to determine if Actl6a promotes neural survival post-SCI by regulating autophagy-related genes Atg5 and Atg7 through Sox2. It also examines how the demethylase Fto modulates Actl6a mRNA stability via m6A methylation.

METHODS

In vitro experiments were conducted using primary neurons and HT-22 hippocampal cells exposed to hydrogen peroxide (H2O2)-induced oxidative stress. Actl6a expression was manipulated by knockdown or overexpression. For in vivo studies, a rat SCI model was established with AAV-Actl6a injected at the injury site to induce Actl6a overexpression. Autophagy and apoptosis markers were analyzed using immunofluorescence, Western blotting, and qPCR. Additionally, m6A dot blot and RNA immunoprecipitation (RIP) assays were performed to assess Fto's role in regulating Actl6a mRNA methylation and stability.

RESULTS

Actl6a expression significantly decreased after SCI, resulting in increased apoptosis. Overexpressing Actl6a enhanced autophagy, reduced apoptosis, and improved neurological function in SCI models. Mechanistically, Actl6a and Sox2 collaboratively upregulated Atg5 and Atg7 expression, promoting autophagy. Fto's modulation of Actl6a mRNA stability via m6A demethylation further influenced autophagy and apoptosis.

CONCLUSION

Actl6a, through interaction with Sox2, plays a critical role in modulating autophagy and reducing apoptosis in SCI, with Fto's m6A modification affecting Actl6a stability. This Fto/Actl6a/Sox2 axis is a promising therapeutic target for SCI repair.

Sulforaphane suppresses cell proliferation and induces apoptosis in glioma via the ACTL6A/PGK1 axis

This study aimed to examine the expression and biological functions of ACTL6A in glioma cells (U251), the effects of sulforaphane on the growth of U251 cells and the involvement of the ACTL6A/PGK1 pathway in those effects. The U251 cell line was transfected with ACTL6A over-expression plasmids to upregulate the protein, or with ACTL6A inhibitor to underexpress it, then treated with different concentrations of sulforaphane. Cell viability, proliferation, and apoptosis were assessed using standard assays, and levels of mRNAs encoding ACTL6A, PGK1, cyclin D1, Myc, Bax or Bcl-2 were measured using quantitative real-time polymerase chain reaction (qRT-PCR). ACTL6A and PGK1 were expressed at higher levels in glioma cell lines than in normal HEB cells. ACTL6A overexpression upregulated PGK1, whereas ACTL6A inhibition had the opposite effect. ACTL6A overexpression induced proliferation, whereas its inhibition repressed proliferation, enhanced apoptosis, and halted the cell cycle. Moreover, sulforaphane suppressed the growth of U251 cells by inactivating the ACTL6A/PGK1 axis. ACTL6A acts via PGK1 to play a critical role in glioma cell survival and proliferation, and sulforaphane targets it to inhibit glioma.

ACTL6A: unraveling its prognostic impact and paving the way for targeted therapeutics in carcinogenesis

Introduction: Increased Actin-like 6A (ACTL6A) expression is associated with various cancers, but its comprehensive investigation across different malignancies is lacking. We aimed to analyze ACTL6A as a potential oncogene and therapeutic target using bioinformatics tools. Methods: We comprehensively analyzed ACTL6A expression profiles across human malignancies, focusing on correlations with tumor grade, stage, metastasis, and patient survival. Genetic alterations were examined, and the epigenetic landscape of ACTL6A was assessed using rigorous methods. The impact of ACTL6A on immune cell infiltration in the tumor microenvironment was evaluated, along with molecular docking studies and machine learning models. Results: Our analysis revealed elevated ACTL6A expression in various tumors, correlating with poor prognostic indicators such as tumor grade, stage, metastasis, and patient survival. Genetic mutations and epigenetic modifications were identified, along with associations with immune cell infiltration and key cellular pathways. Machine learning models demonstrated ACTL6A's potential for cancer detection. Discussion: ACTL6A emerges as a promising diagnostic and therapeutic target in cancer, with implications for prognosis and therapy. Our study provides comprehensive insights into its carcinogenic actions, highlighting its potential as both a prognostic indicator and a target for anti-cancer therapy. This integrative approach enhances our understanding of ACTL6A's role in cancer pathogenesis and treatment.

Gene amplification of chromatin remodeling factor SMARCC2 and low protein expression of ACTL6A are unfavorable factors in ovarian high‑grade serous carcinoma

Ovarian high-grade serous carcinoma (OHGSC) is the most common type of ovarian cancer worldwide. Genome sequencing has identified mutations in chromatin remodeling factors (CRFs) in gynecological cancer, such as clear cell carcinoma, endometrioid carcinoma and endometrial serous carcinoma. However, to the best of our knowledge, the association between CRFs and OHGSC remains unexplored. The present study aimed to investigate the clinicopathological and molecular characteristics of CRF dysfunction in OHGSC. CRF alterations were analyzed through numerous methods, including the analysis of public next-generation sequencing (NGS) data from 585 ovarian serous carcinoma cases from The Cancer Genome Atlas (TCGA), immunohistochemistry (IHC), and DNA copy number assays, which were performed on 203 surgically resected OHGSC samples. In the public NGS dataset, the most frequent genetic alteration was actin-like protein 6A (ACTL6A) amplification at 19.5%. Switch/sucrose non-fermentable related, matrix associated, actin dependent regulator of chromatin subfamily c member 2 (SMARCC2) amplification (3.1%) was associated with significantly decreased overall survival (OS). In addition, chromodomain-helicase-DNA-binding protein 4 (CHD4) amplification (5.7%) exhibited unfavorable outcome trends, although not statistically significant. IHC revealed the protein expression loss of ARID1A (2.5%), SMARCA2 (2.5%) and SMARCA4 (3.9%). The protein expression levels of ACTL6A, SMARCC2 and CHD4 were evaluated using H-score. Patients with low protein expression levels of ACTL6A showed a significantly decreased OS. Copy number gain or gene amplification was demonstrated in ACTL6A (66.2%) and SMARCC2 (33.5%), while shallow deletion or deep deletion was demonstrated in CHD4 (70.7%). However, there was no statistically significant difference in protein levels of these CRFs, between the different copy number alterations (CNAs). Overall, OHGSC exhibited CNAs and protein loss, indicating possible gene alterations in CRFs. Moreover, there was a significant association between the protein expression levels of ACTL6A and poor prognosis. Based on these findings, it is suggested that CRFs could serve as prognostic markers for OHGSC.

Correlation of NPDC1 Expression and Perineural Invasion Status with Clinicopathological Features in Patients with Colon Cancer

Background

Colon cancer is a prevalent gastrointestinal malignancy that often exhibits distant metastasis, hindering the effectiveness of surgical interventions. In addition to well-known hematogenous and lymphatic metastasis, perineural invasion (PNI) has emerged as a significant mode of distant metastasis in colon tumors. PNI is closely associated with oncologic pain in advanced cancer patients, but the underlying mechanisms and associated biomarkers, which might be the novel therapeutic targets, remain poorly understood.

Methods

In this study, we employed large databases and bioinformatics methods to identify genes strongly linked to PNI in colon cancer and investigated their involvement in tumor nerve invasion, progression mechanisms, and chemotherapy resistance. Immunohistochemical techniques were utilized to validate the expression of target genes in 384 colon cancer tissues, and their expression was correlated with clinicopathological characteristics and patient survival data in our hospital. Furthermore, we conducted a comprehensive literature review to explore the potential functions of the target genes and their associated genes.

Results

Our screening revealed a significant correlation between neural proliferation differentiation and control-1 (NPDC1) expression and patient prognosis, suggesting a potential association with neural infiltration in colon cancer. Additionally, NPDC1 may promote tumorigenesis, progression, and chemoresistance through various related pathways.

Conclusion

Our study provides novel insights into the utility of NPDC1 as a predictive marker for PNI status, disease-free survival, and overall survival in patients with colon cancer, highlighting the prevalence of NPDC1 overexpression in patients with PNI in colon cancer.

ACTL6A protects gastric cancer cells against ferroptosis through induction of glutathione synthesis

Gastric cancer (GC), one of the most common malignant tumors in the world, exhibits a rapid metastasis rate and causes high mortality. Diagnostic markers and potential therapeutic targets for GCs are urgently needed. Here we show that Actin-like protein 6 A (ACTL6A), encoding an SWI/SNF subunit, is highly expressed in GCs. ACTL6A is found to be critical for regulating the glutathione (GSH) metabolism pathway because it upregulates γ-glutamyl-cysteine ligase catalytic subunit (GCLC) expression, thereby reducing reactive oxygen species (ROS) levels and inhibiting ferroptosis, a regulated form of cell death driven by the accumulation of lipid-based ROS. Mechanistic studies show that ACTL6A upregulates GCLC as a cotranscription factor with Nuclear factor (erythroid-derived 2)-like 2 (NRF2) and that the hydrophobic region of ACTL6A plays an important role. Our data highlight the oncogenic role of ACTL6A in GCs and indicate that inhibition of ACTL6A or GCLC could be a potential treatment strategy for GCs.

Actin-like Protein 6A Expression Correlates with Cancer Stem Cell-like Features and Poor Prognosis in Ovarian Cancer

Ovarian cancer has the highest mortality rate among gynecological cancers, often diagnosed at the late stage and lacking an effective targeted therapy. Although the study of malignant features of cancer, considered to be cancer stem cells (CSCs), is emerging, the aim of this study was to predict and explore the possible mechanism and clinical value of genetic markers in the development of ovarian cancer from a combined database with CSCs features. The common differentially expressed genes (DEGs) were selected in GSE185833 and GSE176246 datasets from the Gene Expression Omnibus (GEO). The GSE185833 dataset was created to reveal gene expression profiles of peritoneal metastasis tissues using single-cell sequencing, and the GSE176246 dataset was determined from gene expression profiles of chemotherapy-refractory ovarian cancer cell lines compared with ovarian cancer cell lines by RNA-seq analysis. By analyzing the correlation between common DEGs and prognosis of ovarian cancer and its possible pathways and functions were predicted by The Cancer Genome Atlas (TCGA) database. The expression levels of 11 genetic markers were significantly elevated in highly invasive and chemoresistant ovarian cancer. The expression of Actin-like protein 6A (ACTL6A) was found to be correlated with survival prognosis, and the total survival time of the patients with high expression of ACTL6A was shorter than those with low expression. Gene set enrichment analysis (GSEA) showed that ACTL6A positively enriched the gene set of 'Cell cycle' and ACTL6A negatively enriched the gene set of focal adhesion. CP724714, a human epidermal growth factor receptor 2 (HER2) inhibitor, could serve as a therapeutic option when ACTL6A levels are high in ovarian cancer cells. The high expression of ACTL6A is a poor prognostic factor in ovarian cancer and may serve as an effective biomarker for predicting treatment-refractory, metastasis, and prognosis of patients with ovarian cancer. The use of HER2 inhibitors is a promising therapeutic strategy against chemoresistant ovarian cancer.

Protective role of Decylubiquinone against secondary melanoma at lung in B16F10 induced mice by reducing E-cadherin expression and ameliorating ROCKII-Limk1/2-Cofiliin mediated metastasis

Melanoma is one of the most consequential skin cancer with a rising death incidences. Silent but belligerent nature of metastatic sprouting is the leading cause of melanoma related mortality. Invasion of metastatic cells and re-expression of E-Cadherin play the crucial role in the establishment of secondary tumor at distal sites. Thus, manipulation of tumor cell invasion in parallel to regulation of E-Cadherin expression can be considered as potential anti-metastatic strategy. Evidences suggested key role of reactive oxygen species associated ROCK activities in the modulation of metastatic invasion via F-actin stabilization. Here, we first-time report Decylubiquinone, a dietary Coenzyme Q₁₀ analog, as an effective attenuator of pulmonary metastatic melanoma in C57BL/6 mice. Current study depicted detailed molecular interplay associated with Decylubiquinone mediated phosphorylation of ROCKII at Tyr722 along with reduced phosphorylation of ROCKII Ser1366 leading to suppression of Limk1/2-Cofilin-F-actin stabilization axis that finally restricted B16F10 melanoma cell invasion at metastatic site. Analysis further deciphered the role of HNF4α as its nuclear translocation modulated E-Cadherin expression, the effect of reactive oxygen species dependent ROCKII activity in secondarily colonized B16F10 melanoma cells at lungs. Thus unbosoming of related signal orchestra represented Decylubiquinone as a potential remedial agent against secondary lung melanoma.

BAF53A drives colorectal cancer development by regulating DUSP5-mediated ERK phosphorylation

BAF53A, an important subunit of the SWI/SNF epigenetic chromatin regulatory complex, has been implicated as the driver of diverse cancers. However, the role of BAF53A in colorectal cancer (CRC) remains poorly understood. Here, we examined the expression of BAF53A in CRC samples and observed that BAF53A was significantly upregulated in CRC tissues compared with paired adjacent normal tissues. In vitro and in vivo studies suggested that ectopic expression of BAF53A promoted colorectal cancer cell proliferation, colony formation, and tumorigenesis, whereas knockdown of BAF53A hindered these cellular functions. DUSP5 (dual-specificity phosphatase 5), an ERK1/2-specific endogenous phosphatase, was expressed at low levels in CRC. We found a negative correlation between BAF53A and DUSP5 expression in a set of CRC samples. Mechanistic studies revealed that P63 was a potential transcription repressor of DUSP5. BAF53A could interact with P63, decreasing the DUSP5 expression level and subsequently promoting ERK1/2 phosphorylation. Thus, our study provides insights into the applicability of the BAF53A-DUSP5-ERK1/2 axis as a potential therapeutic target in CRC.

Dissecting novel mechanisms of hepatitis B virus related hepatocellular carcinoma using meta-analysis of public data

BACKGROUND

Hepatitis B virus (HBV) is a cause of hepatocellular carcinoma (HCC). Interestingly, this process is not necessarily mediated through cirrhosis and may in fact involve oncogenic processes. Prior studies have suggested specific oncogenic gene expression pathways were affected by viral regulatory proteins. Thus, identifying these genes and associated pathways could highlight predictive factors for HCC transformation and has implications in early diagnosis and treatment.

AIM

To elucidate HBV oncogenesis in HCC and identify potential therapeutic targets.

METHODS

We employed our Search, Tag, Analyze, Resource platform to conduct a meta-analysis of public data from National Center for Biotechnology Information’s Gene Expression Omnibus. We performed meta-analysis consisting of 155 tumor samples compared against 185 adjacent non-tumor samples and analyzed results with ingenuity pathway analysis.

RESULTS

Our analysis revealed liver X receptors/retinoid X receptor (RXR) activation and farnesoid X receptor/RXR activation as top canonical pathways amongst others. Top upstream regulators identified included the Ras family gene rab-like protein 6 (RABL6). The role of RABL6 in oncogenesis is beginning to unfold but its specific role in HBV-related HCC remains undefined. Our causal analysis suggests RABL6 mediates pathogenesis of HBV-related HCC through promotion of genes related to cell division, epigenetic regulation, and Akt signaling. We conducted survival analysis that demonstrated increased mortality with higher RABL6 expression. Additionally, homeobox A10 (HOXA10) was a top upstream regulator and was strongly upregulated in our analysis. HOXA10 has recently been demonstrated to contribute to HCC pathogenesis in vitro. Our causal analysis suggests an in vivo role through downregulation of tumor suppressors and other mechanisms.

CONCLUSION

This meta-analysis describes possible roles of RABL6 and HOXA10 in the pathogenesis of HBV-related HCC. RABL6 and HOXA10 represent potential therapeutic targets and warrant further investigation.

GBA1-dependent membrane glucosylceramide reprogramming promotes liver cancer metastasis via activation of the Wnt/β-catenin signalling pathway

The effect of glucosylceramide (GlcCer) reprogramming on liver cancer metastasis remains poorly understood. In this study, we demonstrated that the protein expression of GBA1, which catalyses the conversion of GlcCer to ceramide, was downregulated in liver cancer tissue. A clinical relevance analysis revealed that low expression of GBA1 was associated with the metastatic potential of liver cancer cells. Furthermore, loss- and gain-of-function studies confirmed that low expression of GBA1 promoted metastasis of liver cancer both in vitro and in vivo. Mechanistic studies indicated that low expression of GBA1 enhanced the metastatic ability of liver cancer by promoting the epithelial-mesenchymal transition (EMT), in which Wnt signalling pathway is involved. In the plasma membrane (PM), GBA1-dependent GlcCer reprogramming increased LRP6 location in the PM leading to an interaction between GlcCer and LRP6, subsequently promoting LRP6 phosphorylation at Ser1490, and finally activating the Wnt/β-catenin signalling pathway. To our knowledge, this is the first time to be found that GlcCer interacted with a protein. In addition, the results of mass spectrometry indicated that GlcCer d18:1/18:0 was the most notably increased studied species in the PM when GBA1 was downregulated, suggesting that GlcCer d18:1/18:0 may be the major functional lipid that promotes GBA1-dependent liver cancer metastasis. Thus, GBA1-mediated GlcCer reprogramming in the PM promotes metastasis of liver cancer via activation of the Wnt/β-catenin signalling pathway, upregulation of GBA1 may be a potential therapeutic strategy to combat liver cancer metastasis.

Upregulated Expression of Actin-Like 6A is a Risk Factor Affecting the Prognosis of Pancreatic Cancer

Purpose

Actin-like 6A (ACTL6A), a regulatory subunit of the ATP-dependent chromatin-remodeling complex SWI/SNF, acts as an oncogenic factor. This study is aimed at evaluating the correlation between ACTL6A expression and clinicopathological parameters in pancreatic cancer (PC) patients.

Methods

The differences of Actl6a mRNA expression between PC tissues and normal pancreatic tissues were analyzed in public databases, and ACTL6A expression was then determined and confirmed in 60 paired tissue specimens using immunohistochemistry staining. The association analysis between ACTL6A expression and the clinicopathological characteristics was analyzed, as well as Kaplan–Meier survival analysis. Univariate and multivariate Cox analyses were performed to identify the prognostic factors in the overall survival (OS) of patients with PC.

Results

The mRNA expression of Actl6a showed significantly higher in PC compared to normal controls (p < 0.05) from public databases. The score of immunohistochemistry staining further confirmed that ACTL6A expression was significantly upregulated in PC tissues (p < 0.001) through immunohistochemistry staining. High ACTL6A expression was associated with lymphovascular space invasion of PC. Kaplan–Meier analysis revealed that the high expression of ACTL6A was markedly associated with poor OS. Moreover, univariate and multivariate analysis demonstrated that ACTL6A acted as an independent risk factor for PC prognosis.

Conclusion

ACTL6A is upregulated in PC and acts as a risk factor for poor prognosis in patients with PC, and therefore clinicians could around it design preventive measures and individualized treatment to improve mortality in patients with PC.

Potential Role of SWI/SNF Complex Subunit Actin-Like Protein 6A in Cervical Cancer

SWI/SNF complex subunit Actin-like protein 6A (ACTL6A) has been regarded as an oncogene, regulating the proliferation, migration and invasion of cancer cells. However, the expression pattern and biological role of ACTL6A in cervical cancer have not been reported. In this study, the mRNA expression and protein level of ACTL6A in cervical cancer samples were determined by public database and immunohistochemical (IHC) analysis. The effects of ACTL6A on cervical cancer cells were investigated via MTT, colony-formation assay, tumor xenografts and flow cytometry. Gene set enrichment analysis (GSEA) was used to explore the potential mechanism of ACTL6A in regulating tumorigenesis of cervical cancer. The results revealed that ACTL6A was markedly upregulated in cervical cancer tissues. Silencing ACTL6A expression resulted in decreased cervical cancer cell proliferation, colony formation and tumorigenesis in vitro and in vivo. Furthermore, we demonstrated that knockdown of ACTL6A induced cell cycle arrest at G1 phase, ACTL6A-mediated proliferation and cell cycle progression were c-Myc dependent. Our study provides the role of ACTL6A in cervical oncogenesis and reveals a potential target for therapeutic intervention in this cancer type.

ACTL6A promotes repair of cisplatin-induced DNA damage, a new mechanism of platinum resistance in cancer

Cisplatin is a mainstay of systemic therapy for a variety of cancers, such as lung cancer, head and neck cancer, and ovarian cancer. However, resistance to cisplatin represents one of the most significant barriers for patient outcome improvement. Actin-like 6A (ACTL6A) is a component of several chromatin remodeling complexes, including SWI/SNF, NuA4/TIP60 histone acetylase, and INO80. Amplification of ACTL6A gene is often seen in lung squamous cell carcinoma, ovarian cancer, and esophageal cancer, but its significance remains to be fully determined. Here we identify ACTL6A overexpression as a novel cause for platinum resistance. High levels of ACTL6A are associated with chemoresistance in several types of human cancer. We show that overexpression of ACTL6A leads to increased repair of cisplatin-DNA adducts and resistance to cisplatin treatment. In contrast, depletion of ACTL6A inhibits the repair of cisplatin-induced DNA lesions, and increases cisplatin sensitivity in cisplatin-resistant ovarian cancer cells. The regulation of repair by ACTL6A is mediated through the SWI/SNF chromatin remodeling complex. Treatment with a histone deacetylase inhibitor can reverse the effect of ACTL6A overexpression on the repair of cisplatin-induced DNA damage and render cancer cells more sensitive to cisplatin treatment in a xenograft mouse model. Taken together, our study uncovers a novel role for ACTL6A in platinum resistance, and provides evidence supporting the feasibility of using HDAC inhibitors for platinum resistant tumors.

Characteristics of colorectal carcinoma patients with PMS2 defects detected by immunohistochemistry

Lynch syndrome is the most prevalent form of familial colorectal cancer (CRC) and is caused by pathogenic germline mismatch repair (MMR) gene mutations. MLH1, MSH2 and MSH6 mutations have been well studied, but the rate and characteristics of PMS2 mutations are rare, especially in China. This study enrolled 1706 unselected patients with CRC who underwent colorectal resection from June 2016 to November 2018, the MMR status and clinicopathological features were analysed. A total of 11.8% of patients with CRC had defects in at least one MMR-related protein. Among them, 8.3% were identified with PMS2 defects, and 3.1% of patients had isolated PMS2 defects. Compared with MMR-proficient CRC, PMS2-defect CRC occurred more frequently in the right colon and less frequently in the rectum, had more poorly differentiated and mucinous carcinoma cases, and had fewer perineural invasions and a lower pN stage but a more advanced pT stage and a larger tumour size. In the cases with PMS2 defect, there were fewer tumours in the right colon, fewer poorly differentiated cases and smaller tumour sizes than in the cases with both MLH1 and PMS2 defects. In addition, in cases with isolated PMS2 defects, there were more tumours in the right colon and, more mucinous carcinoma cases than in cases with MMR-proficient CRCs, but had a similar cancer onset age. This study identified the rate, clinicopathological and age characteristics of PMS2 defects in CRCs in China and highlighted the importance of universal screening and germline detection of PMS2 in CRC.

ACTL6A promotes the growth in non-small cell lung cancer by regulating Hippo/Yap pathway

Purpose: To delve into the related molecular mechanism of ACTL6A on non-small cell lung cancer (NSCLC) cell growth and apoptosis.Methods: Quantitative real-time polymerase chain reaction, immunohistochemical staining, and western blot assays were employed to examine ACTL6A mRNA and protein expression in four NSCLC cell line (NCI-H2170, LTEP-s, NCI-H1703, and PC-9) and normal lung cell line (BEAS-2B). CCK-8 cell viability assays and clone formation assay were applied to verify the cell proliferation of NCI-H2170 cell line after knockdown of ACTL6A. Flow cytometry assays were applied to check the role of ACTL6A in the apoptosis of NSCLC cells. The western blot assays were employed to examine the protein expression of WWC1, YAP, TAZ, and CYR61 in NCI-H2170 after knockdown of ACTL6A. Finally, xenograft tumor was taken out and checked the tumor volumes and weight. Immunohistochemical staining and western blot assays were employed to examine cell proliferation and apoptosis of NSCLC in vivo.Results: In this study, the results showed that the mRNA and protein expression level of ACTL6A was higher in four NSCLC cell line than normal lung cell line, respectively. Suppression of ACTL6A inhibited the growth and promoted apoptosis of NSCLC cells. Meanwhile, ACTL6A promotes tumor growth and inhibits apoptosis of NSCLC in vivo via Hippo/YAP signaling pathway.Conclusion: ACTL6A promotes the proliferation in NSCLC by regulating Hippo/YAP pathway.

LncRNA SNHG19 Promotes the Development of Non-Small Cell Lung Cancer via Mediating miR-137/E2F7 Axis

Objective

Non-small cell lung cancer (NSCLC) is a common malignant tumor, which has high incidence and low the 5-year survival rate. Long non-coding RNAs (lncRNAs) play critical roles in carcinoma occurrence and metastasis. Herein, our aim was to investigate the effects of lncRNA SNHG19 in NSCLC progression.

Materials and Methods

Long non-coding RNA Small Nucleolar RNA Host Gene 19 (lncRNA SNHG19) expression level was measured by bioinformatics and qRT-PCR. Edu, Transwell, and scratch assays were performed to explore the role of si-SNHG19 or SNHG19 on NSCLC progression. Luciferase assay was used to verify the relationship between SNHG19/E2F7 and miR-137. The experiment of Xenograft was used for exploring the function of SNHG19 in vivo.

Results

SNHG19 was upregulated in cancer tissues, patients plasma and cell lines of NSCLC. Knockdown of SNHG19 inhibited cell proliferation, migration, and invasion. Luciferase assay confirmed that SNHG19 regulated E2F7 expression via interacting with miR-137. Overexpression of SNHG19 accelerated NSCLC tumor progression via miR-137/E2F7 axis both in vitro and in vivo.

Conclusions

Our results clarified the SNHG19 function for the first time, and SNHG19 promoted the progression of NSCLC, which was mediated by the miR-137/E2F7 axis. This study might provide new understanding and targets for NSCLC diagnosis and treatment.

M2 macrophage-derived exosomal microRNA-155-5p promotes the immune escape of colon cancer by downregulating ZC3H12B

Previous evidence has highlighted M2 macrophage regulation of cancer cells via exosome shuttling of microRNAs (miRNAs or miRs). The current study set out to explore the possible role of M2 macrophage-derived exosomal miR-155-5p in regard to immune escape of colon cancer cells. Experimental data from quantitative reverse-transcriptase PCR (qRT-PCR) and western blot analysis revealed highly expressed miR-155-5p and interleukin (IL)-6 and poorly expressed ZC3H12B in M2 macrophage-derived exosomes. Additionally, miR-155-5p could be transferred by M2 macrophage-isolated exosomes to colon cancer cells, which targeted ZC3H12B by binding to the 3¢ UTR, as identified by dual luciferase reporter gene. Meanwhile, gain- and loss-of function experimentation on miR-155-5p and ZC3H12B in SW48 and HT29 cells cocultured with M2 macrophage-secreted exosomes demonstrated that miR-155-5p overexpression or ZC3H12B silencing promoted the proliferation and antiapoptosis ability of SW48 and HT29 cells, as well as augmenting the CD3⁺ T cell proliferation and the proportion of interferon (IFN)-γ⁺ T cells. Xenograft models confirmed that M2 macrophage-derived exosomal miR-155-5p reduced the ZC3H12B expression to upregulate IL-6, which consequently induced immune escape and tumor formation. Collectively, our findings indicated that M2 macrophage-derived exosomal miR-155-5p can potentially promote the immune escape of colon cancer by impairing ZC3H12B-mediated IL-6 stability reduction, thereby promoting the occurrence and development of colon cancer.

Actin-like protein 6A/MYC/CDK2 axis confers high proliferative activity in triple-negative breast cancer

Background

Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer with high proliferative activity. TNBC tumors exhibit elevated MYC expression and altered expression of MYC regulatory genes, which are associated with tumor progression and poor prognosis; however, the underlying mechanisms by which MYC retains its high expression and mediates TNBC tumorigenesis require further exploration.

Methods

ACTL6A regulation of MYC and its target gene, CDK2, was defined using Co-IP, mass spectrometry and ChIP assays. To study the role of ACTL6A in TNBC, we performed soft-agar, colony formation, flow cytometry and tumor formation in nude mice. CDK2 inhibitor and paclitaxel were used in testing combination therapy in vitro and in vivo.

Results

ACTL6A bound MYC to suppress glycogen synthase kinase 3 beta (GSK3β)-induced phosphorylation on MYC T58, which inhibited ubiquitination of MYC and stabilized it. Moreover, ACTL6A promoted the recruitment of MYC and histone acetyltransferase KAT5 on CDK2 promoters, leading to hyperactivation of CDK2 transcription. ACTL6A overexpression promoted, while silencing ACTL6A suppressed cell proliferation and tumor growth in TNBC cells in vitro and in vivo, which was dependent on MYC signaling. Furthermore, co-therapy with paclitaxel and CDK2 inhibitor showed synergistic effects in tumor suppression. Notably, ACTL6A/MYC/CDK2 axis was specifically up-regulated in TNBC and high expression of ACTL6A was correlated to shorter survival in patients with TNBC.

Conclusions

These findings reveal a novel mechanism by which ACTL6A prolongs the retention of MYC in TNBC and suggest that pharmacological targeting ACTL6A/MYC/CDK2 axis might have therapeutic potential in patients with TNBC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01856-3.

ACTL6A Promotes the Proliferation of Esophageal Squamous Cell Carcinoma Cells and Correlates with Poor Clinical Outcomes

Background

ACTL6A, a regulatory subunit of ATP-dependent chromatin-remodeling complexes SWI/SNF, has been identified as a central oncogenic driver in many tumor types.

Materials and Methods

We used immunohistochemistry (IHC) to detect ACTL6A expression in esophageal squamous cell carcinoma (ESCC) tissues. Then, the effect of ACTL6A on proliferation and DNA synthesis was explored by using cell counting kit 8 (CCK8) and EdU retention assays. The potential oncogenic mechanism of ACTL6A in ESCC cells was also analyzed by flow cytometry and Western blotting. We further established an ESCC xenograft mouse model to validate the in vitro results.

Results

ACTL6A expression, localized in cancer cell nuclei, was markedly higher in ESCC tissues than in the corresponding noncancerous tissues (P<0.001) and was positively associated with tumor size, histological differentiation, T stage and tumor-node-metastasis (TNM) stage. Kaplan–Meier analysis revealed that high ACTL6A expression was significantly associated with poor overall survival (OS) (P = 0.008, HR= 2.562, 95% CI: 1.241–5.289), and decision curve analysis (DCA) demonstrated that ACTL6A could increase the clinical prognostic efficiency of the original clinical prediction model. Further in vitro experiments showed that ACTL6A knockdown led to inhibition of cell proliferation and DNA synthesis in ESCC cell lines, while overexpression of ACTL6A had the opposite effects. ACTL6A knockdown resulted in G1 phase arrest, with downregulation of cyclin D1, CDK2 and S6K1/pS6 pathway proteins and upregulation of p21 and p27, while overexpression of ACTL6A facilitated the entry of more cells into S phase with upregulated cyclin D1, CDK2 and S6K1/pS6 pathway proteins and downregulated p21 and p27. Finally, a xenograft mouse model of ESCC cells validated the results in vitro.

Conclusion

ACTL6A expression may affect the proliferation and DNA synthesis of ESCC cells by facilitating ESCC cell cycle redistribution via the S6K1/pS6 pathway. Therefore, ACTL6A may potentially become an alternative therapeutic target for ESCC.

ACTL6A knockdown inhibits cell migration by suppressing the AKT signaling pathway and enhances the sensitivity of glioma cells to temozolomide

Molecular-targeted therapy has had a significant impact on glioma. Notably, actin-like 6A (ACTL6A) has been indicated to be essential for embryonic development and tumor progression. However, the role of ACTL6A in glioma remains unclear. The present study aimed to investigate the effects of ACTL6A on glioma cell migration and sensitivity to temozolomide (TMZ). The expression levels of ACTL6A were analyzed in patients with glioma, and survival curves were created using data from The Cancer Genome Atlas. U251 and T98G cells were transfected with short hairpin (sh)RNA for use in loss-of-function experiments to investigate the biological function and molecular mechanisms of ACTL6A. Furthermore, an MTT assay was used to assess the effect of ACTL6A on the sensitivity of glioma cells to TMZ. The results demonstrated that ACTL6A was expressed at higher levels in glioma tissues compared with normal brain tissues. Furthermore, high expression of ACTL6A was associated with a poor prognosis. The knockdown of ACTL6A significantly inhibited the migration phenotype in glioma cells and significantly decreased the levels of phosphorylated AKT in glioma cells. The AKT signaling activator SC79 partly attenuated the inhibitory effects of ACTL6A shRNA on glioma cell migration. Additionally, the knockdown of ACTL6A enhanced the sensitivity of glioma cells to TMZ. In conclusion, these results suggest that ACTL6A knockdown inhibited the migration of human glioma cells, at least in part through inactivation of the AKT signaling pathway, and increased the sensitivity of glioma cells to TMZ. Therefore, ACTL6A may be a potential therapeutic target for glioma.

Convergent network effects along the axis of gene expression during prostate cancer progression

Background

Tumor-specific genomic aberrations are routinely determined by high-throughput genomic measurements. It remains unclear how complex genome alterations affect molecular networks through changing protein levels and consequently biochemical states of tumor tissues.

Results

Here, we investigate the propagation of genomic effects along the axis of gene expression during prostate cancer progression. We quantify genomic, transcriptomic, and proteomic alterations based on 105 prostate samples, consisting of benign prostatic hyperplasia regions and malignant tumors, from 39 prostate cancer patients. Our analysis reveals the convergent effects of distinct copy number alterations impacting on common downstream proteins, which are important for establishing the tumor phenotype. We devise a network-based approach that integrates perturbations across different molecular layers, which identifies a sub-network consisting of nine genes whose joint activity positively correlates with increasingly aggressive tumor phenotypes and is predictive of recurrence-free survival. Further, our data reveal a wide spectrum of intra-patient network effects, ranging from similar to very distinct alterations on different molecular layers.

Conclusions

This study uncovers molecular networks with considerable convergent alterations across tumor sites and patients. It also exposes a diversity of network effects: we could not identify a single sub-network that is perturbed in all high-grade tumor regions.

Identification of a Twelve-Gene Signature and Establishment of a Prognostic Nomogram Predicting Overall Survival for Medulloblastoma

BACKGROUND

Medulloblastoma is the common pediatric malignant tumor with poor prognosis in cerebellum. However, MB is always with clinical heterogeneity. To provide patients with more clinically beneficial treatment strategies, there is a pressing need to develop a new prognostic prediction model as a supplement to the prediction outcomes of clinical judgment.

MATERIALS AND METHODS

Four datasets of mRNA expression and clinical data were downloaded from gene expression omnibus (GEO) database. Differentially expressed genes (DEGs) were identified and functionally enriched among GSE50161, GSE74195, GSE86574. Then we used STRING and Cytoscape to constructed and analyze protein-protein interaction network (PPI) and hub genes. Univariate cox regression analysis was performed to identify overall survival-related hub genes in an unique dataset from GSE85217 as train cohort. Lasso Cox regression model was used to construct the prognostic gene signature. Time-dependent receiver operating characteristic (ROC), Kaplan-Meier curve, univariate and multivariate Cox regression analysis were used to assess the prognostic capacity of the twelve-gene signature. A unique dataset from GSE85217 was downloaded to further validate the results. Finally, we established the nomogram by using the gene signature and validated it with ROC curve. Gene set enrichment analysis (GSEA) was carried out to further investigate its potential molecular mechanism. Besides, the twelve genes expression at the mRNA and protein levels was validated using external database such as Oncomine, cBioportal and HPA, respectively.

RESULTS

A twelve-gene signature comprising FOXM1, NEK2, CCT2, ACTL6A, EIF4A3, CCND2, ABL1, SYNCRIP, ITGB1, NRXN2, ENAH, and UMPS was established to predict overall survival of medulloblastoma. The ROC curve showed good performance in survival prediction in both the train cohort and the validation cohort. The twelve-gene signature could stratify patients into a high risk and low risk group which had significantly different survival. Univariate and multivariate Cox regression revealed that the twelve-gene signature was an independent prognostic factor in medulloblastoma. Nomogram, which included twelve-gene signatures, was established and showed some clinical benefit.

CONCLUSION

Our study identified a twelve-gene signature and established a prognostic nomogram that reliably predicts overall survival in medulloblastoma. The above results will help us to better analyze the pathogenesis and treatment of medulloblastoma in the future.

MiR-216a-3p suppresses the proliferation and invasion of cervical cancer through downregulation of ACTL6A-mediated YAP signaling

The tumor-suppressive role of microRNA-216a-3p (miR-216a-3p) has been evidenced in multiple tumors. Yet, the relevance of miR-216a-3p in cervical cancer remains undermined. The current study was designed to determine the expression and potential function of miR-216a-3p in cervical cancer. Expression of miR-216a-3p was markedly decreased in cervical cancer and functional assays revealed an inhibitory effect of miR-216a-3p on the proliferation, colony formation, and invasion of cervical cancer. Actin-like 6A (ACTL6A) was identified as a target gene of miR-216a-3p. Elevated ACTL6A expression was detected in cervical cancer, and ACTL6A inhibition exhibited a tumor-suppressive effect. ACTL6A inhibition increased yes-associated protein (YAP) phosphorylation and downregulated YAP-mediated transcriptional activity. ACTL6A restoration or YAP reactivation partially abrogated the miR-216a-3p-mediated antitumor effect in cervical cancer cells. Taken together, these data demonstrate that miR-216a-3p acts as a potential tumor-suppressive miRNA in cervical cancer, which exerts its function through inhibition of YAP signaling via targeting ACTL6A.

The Actin-Family Protein Arp4 Is a Novel Suppressor for the Formation and Functions of Nuclear F-Actin

The crosstalk between actin and actin-related proteins (Arps), namely Arp2 and Arp3, plays a central role in facilitating actin polymerization in the cytoplasm and also in the nucleus. Nuclear F-actin is required for transcriptional regulation, double-strand break repair, and nuclear organization. The formation of nuclear F-actin is highly dynamic, suggesting the involvement of positive and negative regulators for nuclear actin polymerization. While actin assembly factors for nuclear F-actin have been recently described, information about inhibitory factors is still limited. The actin-related protein Arp4 which is predominantly localized in the nucleus, has been previously identified as an integral subunit of multiple chromatin modulation complexes, where it forms a heterodimer with monomeric actin. Therefore, we tested whether Arp4 functions as a suppressor of nuclear F-actin formation. The knockdown of Arp4 (Arp4 KD) led to an increase in nuclear F-actin formation in NIH3T3 cells, and purified Arp4 potently inhibited F-actin formation in mouse nuclei transplanted into Xenopus laevis oocytes. Consistently, Arp4 KD facilitated F-actin-inducible gene expression (e.g., OCT4) and DNA damage repair. Our results suggest that Arp4 has a critical role in the formation and functions of nuclear F-actin.

The Emerging Roles of ATP-Dependent Chromatin Remodeling Complexes in Pancreatic Cancer

Pancreatic cancer is an aggressive cancer with low survival rates. Genetic and epigenetic dysregulation has been associated with the initiation and progression of pancreatic tumors. Multiple studies have pointed to the involvement of aberrant chromatin modifications in driving tumor behavior. ATP-dependent chromatin remodeling complexes regulate chromatin structure and have critical roles in stem cell maintenance, development, and cancer. Frequent mutations and chromosomal aberrations in the genes associated with subunits of the ATP-dependent chromatin remodeling complexes have been detected in different cancer types. In this review, we summarize the current literature on the genomic alterations and mechanistic studies of the ATP-dependent chromatin remodeling complexes in pancreatic cancer. Our review is focused on the four main subfamilies: SWItch/sucrose non-fermentable (SWI/SNF), imitation SWI (ISWI), chromodomain-helicase DNA-binding protein (CHD), and INOsitol-requiring mutant 80 (INO80). Finally, we discuss potential novel treatment options that use small molecules to target these complexes.

ACTL6A regulates follicle-stimulating hormone-driven glycolysis in ovarian cancer cells via PGK1

Enhanced glycolysis has been identified as a hallmark of cancer. As a novel oncogene, ACTL6A is aberrantly amplified in several types of human cancers and has been shown to regulate tumor growth and progression. However, the roles of ACTL6A in the development of ovarian cancer and the regulation of cancer glucose metabolism are mostly unknown. Here we show that ACTL6A is overexpressed in ovarian cancers compared with adjacent non-tumor tissues, and that ACTL6A overexpression correlates with poor prognosis. Silencing of ACTL6A in vitro inhibits proliferation, clonal growth, and migration, and decreases glucose utilization, lactate production, and pyruvate levels of ovarian cancer cells. We found a positive correlation between ACTL6A and PGK1 expression in ovarian cancer tissues. Enforced ACTL6A expression increased PGK1 expression, whereas knockdown of ACTL6A had the opposite effect. Altered ACTL6A expression inhibits the tumorigenicity of ovarian cancer cells in vivo by downregulating PGK1. In addition, the expression of ACTL6A is regulated by follicle-stimulating hormone (FSH) stimulation via PI3K/AKT pathway. Importantly, ACTL6A regulates FSH-enhanced glycolysis in ovarian cancer. Taken together, our findings highlight the critical role of ACTL6A in ovarian cancer development and identify its contribution to glucose metabolism of cancer cells.

The genetic alteration spectrum of the SWI/SNF complex: The oncogenic roles of BRD9 and ACTL6A

SWItch/Sucrose NonFermentable (SWI/SNF) is a set of multi-subunits chromatin remodeling complexes, playing important roles in a variety of biological processes. Loss-of-function mutations in the genes encoding SWI/SNF subunits have been reported in more than 20% of human cancers. Thus, it was widely considered as a tumor suppressor in the past decade. However, recent studies reported that some genes encoding subunits of SWI/SNF complexes were amplified and play oncogenic roles in human cancers. In present study, we summarized the genetic alteration spectrum of SWI/SNF complexes, and firstly systematically estimated both the copy number variations and point mutations of all 30 genes encoding the subunits in this complex. Additionally, the bioinformatics analyses were performed for two significantly amplified genes, ACTL6A and BRD9, to investigate their oncogenic roles in human cancers. Our findings may lay a foundation for the discovery of potential treatment targets in SWI/SNF complexes of cancers.