HOXB13 networking with ABCG1/EZH2/Slug mediates metastasis and confers resistance to cisplatin in lung adenocarcinoma patients

The role of ATP-binding cassette subfamily G member 1 in tumor progression

BACKGROUND

ATP-binding cassette subfamily G member 1 is mostly known as a transporter for intracellular cholesterol efflux, and a number of studies indicate that ABCG1 also functions actively in tumor initiation and progression. This review aimed to provide an overall review of how ABCG1 acts in tumor progression.

METHOD

A comprehensive searching about ABCG1 and tumor was conducted up to November 2023 using proper keywords through databases including PubMed and Web of Science.

RESULT

Overall, ABCG1 plays a crucial role in the development of multiple tumorigenesis. ABCG1 enhances tumor-promoting ability through conferring stem-like properties to cancer cells and mediates chemoresistance in multiple cancers. Additionally, ABCG1 may act as a kinase to phosphorylate downstream molecules and induces tumor growth. In tumor microenvironment, ABCG1 plays a substantial role in immunity response through macrophages to create a tumor-favoring circumstance.

CONCLUSION

High expression of ABCG1 is usually associated with poor prognosis, which means ABCG1 may be a potential biomarker for early diagnosis and prognosis of various cancers. ABCG1-targeted therapy may provide a novel treatment for cancer patients.

A Comprehensive Analysis of HOXB13 Expression in Hepatocellular Carcinoma

Background and objectives: Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and is caused by multiple factors. To explore novel targets for HCC treatment, we comprehensively analyzed the expression of HomeoboxB13 (HOXB13) and its role in HCC. Materials and Methods: The clinical significance of HCC was investigated using open gene expression databases, such as TIMER, UALCAN, KM, OSlihc, and LinkedOmics, and immunohistochemistry analysis. We also analyzed cell invasion and migration in HCC cell lines transfected with HOXB13-siRNA and their association with MMP9, E2F1, and MEIS1. Results: HOXB13 expression was higher in fibrolamellar carcinoma than in other histological subtypes. Its expression was associated with lymph node metastasis, histological stage, and tumor grade. It was positively correlated with immune cell infiltration of B cells (R = 0.246), macrophages (R = 0.182), myeloid dendritic cells (R = 0.247), neutrophils (R = 0.117), and CD4+ T cells (R = 0.258) and negatively correlated with immune cell infiltration of CD8+ T cells (R = -0.107). A positive correlation was observed between HOXB13, MMP9 (R = 0.176), E2F1 (R = 0.241), and MEIS1 (R = 0.189) expression (p < 0.001). The expression level of HOXB13 was significantly downregulated in both HepG2 and PLC/PFR/5 cell lines transfected with HOXB13-siRNA compared to that in cells transfected with NC siRNA (p < 0.05). Additionally, HOXB13 significantly affected cell viability and wound healing. Conclusions: HOXB13 overexpression may lead to poor prognosis in patients with HCC. Additional in vivo studies are required to improve our understanding of the biological role and the exact mechanism of action of HOXB13 in HCC.

Cholesterol metabolism in tumor microenvironment: cancer hallmarks and therapeutic opportunities

Cholesterol is crucial for cell survival and growth, and dysregulation of cholesterol homeostasis has been linked to the development of cancer. The tumor microenvironment (TME) facilitates tumor cell survival and growth, and crosstalk between cholesterol metabolism and the TME contributes to tumorigenesis and tumor progression. Targeting cholesterol metabolism has demonstrated significant antitumor effects in preclinical and clinical studies. In this review, we discuss the regulatory mechanisms of cholesterol homeostasis and the impact of its dysregulation on the hallmarks of cancer. We also describe how cholesterol metabolism reprograms the TME across seven specialized microenvironments. Furthermore, we discuss the potential of targeting cholesterol metabolism as a therapeutic strategy for tumors. This approach not only exerts antitumor effects in monotherapy and combination therapy but also mitigates the adverse effects associated with conventional tumor therapy. Finally, we outline the unresolved questions and suggest potential avenues for future investigations on cholesterol metabolism in relation to cancer.

Epigenetic reprogramming of T cells: unlocking new avenues for cancer immunotherapy

T cells, a key component of cancer immunotherapy, undergo a variety of histone modifications and DNA methylation changes since their bone marrow progenitor stages before developing into CD8+ and CD4+ T cells. These T cell types can be categorized into distinct subtypes based on their functionality and properties, such as cytotoxic T cells (Tc), helper T cells (Th), and regulatory T cells (Treg) as subtypes for CD8+ and CD4+ T cells. Among these, the CD4+ CD25+ Tregs potentially contribute to cancer development and progression by lowering T effector (Teff) cell activity under the influence of the tumor microenvironment (TME). This contributes to the development of therapeutic resistance in patients with cancer. Subsequently, these individuals become resistant to monoclonal antibody therapy as well as clinically established immunotherapies. In this review, we delineate the different epigenetic mechanisms in cancer immune response and its involvement in therapeutic resistance. Furthermore, the possibility of epi-immunotherapeutic methods based on histone deacetylase inhibitors and histone methyltransferase inhibitors are under investigation. In this review we highlight EZH2 as the principal driver of cancer cell immunoediting and an immune escape regulator. We have addressed in detail how understanding T cell epigenetic regulation might bring unique inventive strategies to overcome drug resistance and increase the efficacy of cancer immunotherapy.

A novel disulfidptosis-related prognostic gene signature and experimental validation identify ACTN4 as a novel therapeutic target in lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD) is a prevalent form of malignancy globally. Disulfidptosis is novel programmed cell death pathway based on disulfide proteins, may have a positive impact on the development of LUAD treatment strategies.

OBJECTIVE

To investigate the impact of disulfidptosis-related genes (DRGs) on the prognosis of LUAD, developed a risk model to facilitate the diagnosis and prognostication of patients. We also explored ACTN4 (DRGs) as a new therapeutic biomarker for LUAD.

METHODS

We investigated the expression patterns of DRGs in both LUAD and noncancerous tissues. To assess the prognostic value of the DRGs, we developed risk models through univariate Cox analysis and lasso regression. The expression and function of ACTN4 was evaluated by qRT-PCR, immunohistochemistry and in vitro experiments. The TIMER examined the association between ACTN4 expression and immune infiltration in LUAD.

RESULTS

Ten differentially expressed DRGs were identified. And ACTN4 was identified as potential risk factors through univariate Cox regression analysis (P< 0.05). ACTN4 expression and riskscore were used to construct a risk model to predict overall survival in LUAD, and high-risk demonstrated a significantly higher mortality rate compared to the low-risk cohort. qRT-PCR and immunohistochemistry assays indicated ACTN4 was upregulated in LUAD, and the upregulation was associated with clinicopathologic features. In vitro experiments showed the knockdown of ACTN4 expression inhibited the proliferation in LUAD cells. The TIMER analysis demonstrated a correlation between the expression of ACTN4 and the infiltration of diverse immune cells. Elevated ACTN4 expression was associated with a reduction in memory B cell count. Additionally, the ACTN4 expression was associated with m6A modification genes.

CONCLUSIONS

Our study introduced a prognostic model based on DRGs, which could forecast the prognosis of patients with LUAD. The biomarker ACTN4 exhibits promise for the diagnosis and management of LUAD, given its correlation with tumor immune infiltration and m6A modification.

LncRNAs in non-small cell lung cancer: novel diagnostic and prognostic biomarkers

Non-small cell lung cancer (NSCLC) is one of the main causes of cancer-related death worldwide, with a serious impact on human health and life. The identification of NSCLC at an early stage is a formidable task that frequently culminates in a belated diagnosis. LncRNA is a kind of noncoding RNA with limited protein-coding capacity, and its expression is out of balance in many cancers, especially NSCLC. A large number of studies have reported that lncRNA acts a vital role in regulating angiogenesis, invasion, metastasis, and the proliferation and apoptosis of tumor cells, affecting the occurrence and development of NSCLC. Abundant evidence demonstrates that lncRNAs may serve as potential biomarkers for NSCLC diagnosis and prognosis. In this review, we summarize the latest progress in characterizing the functional mechanism of lncRNAs involved in the development of NSCLC and further discuss the role of lncRNAs in NSCLC therapy and chemotherapy resistance. We also discuss the advantages, limitations, and challenges of using lncRNAs as diagnostic or prognostic biomarkers in the management of NSCLC.

FERM domain-containing protein FRMD6 activates the mTOR signaling pathway and promotes lung cancer progression

FRMD6, a member of the 4.1 ezrin-radixin-moesin domain-containing protein family, has been reported to inhibit tumor progression in multiple cancers. Here, we demonstrate the involvement of FRMD6 in lung cancer progression. We find that FRMD6 is overexpressed in lung cancer tissues relative to in normal lung tissues. In addition, the enhanced expression of FRMD6 is associated with poor outcomes in patients with lung squamous cell carcinoma (n = 75, P = 0.0054) and lung adenocarcinoma (n = 94, P = 0.0330). Cell migration and proliferation in vitro and tumor formation in vivo are promoted by FRMD6 but are suppressed by the depletion of FRMD6. Mechanistically, FRMD6 interacts and colocalizes with mTOR and S6K, which are the key molecules of the mTOR signaling pathway. FRMD6 markedly enhances the interaction between mTOR and S6K, subsequently increasing the levels of endogenous pS6K and downstream pS6 in lung cancer cells. Furthermore, knocking out FRMD6 inhibits the activation of the mTOR signaling pathway in Frmd6-/- gene KO MEFs and mice. Altogether, our results show that FRMD6 contributes to lung cancer progression by activating the mTOR signaling pathway.

The pharmacological and biological importance of EZH2 signaling in lung cancer

Up to 18% of cancer-related deaths worldwide are attributed to lung tumor and global burden of this type of cancer is ascending. Different factors are responsible for development of lung cancer such as smoking, environmental factors and genetic mutations. EZH2 is a vital protein with catalytic activity and belongs to PCR2 family. EZH2 has been implicated in regulating gene expression by binding to promoter of targets. The importance of EZH2 in lung cancer is discussed in current manuscript. Activation of EZH2 significantly elevates the proliferation rate of lung cancer. Furthermore, metastasis and associated molecular mechanisms including EMT undergo activation by EZH2 in enhancing the lung cancer progression. The response of lung cancer to therapy can be significantly diminished due to EZH2 upregulation. Since EZH2 increases tumor progression, anti-cancer agents suppressing its expression reduce malignancy. In spite of significant effort in understanding modulatory function of EZH2 on other pathways, it appears that EZH2 can be also regulated and controlled by other factors that are described in current review. Therefore, translating current findings to clinic can improve treatment and management of lung cancer patients.

Transcriptomic Signatures of Single-Suture Craniosynostosis Phenotypes

Craniosynostosis is a birth defect where calvarial sutures close prematurely, as part of a genetic syndrome or independently, with unknown cause. This study aimed to identify differences in gene expression in primary calvarial cell lines derived from patients with four phenotypes of single-suture craniosynostosis, compared to controls. Calvarial bone samples (N = 388 cases/85 controls) were collected from clinical sites during reconstructive skull surgery. Primary cell lines were then derived from the tissue and used for RNA sequencing. Linear models were fit to estimate covariate adjusted associations between gene expression and four phenotypes of single-suture craniosynostosis (lambdoid, metopic, sagittal, and coronal), compared to controls. Sex-stratified analysis was also performed for each phenotype. Differentially expressed genes (DEGs) included 72 genes associated with coronal, 90 genes associated with sagittal, 103 genes associated with metopic, and 33 genes associated with lambdoid craniosynostosis. The sex-stratified analysis revealed more DEGs in males (98) than females (4). There were 16 DEGs that were homeobox (HOX) genes. Three TFs (SUZ12, EZH2, AR) significantly regulated expression of DEGs in one or more phenotypes. Pathway analysis identified four KEGG pathways associated with at least one phenotype of craniosynostosis. Together, this work suggests unique molecular mechanisms related to craniosynostosis phenotype and fetal sex.

Polymorphic renal transporters and cisplatin's toxicity in urinary bladder cancer patients: current perspectives and future directions

Urinary bladder cancer (UBC) holds a potentially profound social burden and affects over 573,278 new cases annually. The disease's primary risk factors include occupational tobacco smoke exposure and inherited genetic susceptibility. Over the past 30 years, a number of treatment modalities have emerged, including cisplatin, a platinum molecule that has demonstrated effectiveness against UBC. Nevertheless, it has severe dose-limiting side effects, such as nephrotoxicity, among others. Since intracellular accumulation of platinum anticancer drugs is necessary for cytotoxicity, decreased uptake or enhanced efflux are the root causes of platinum resistance and response failure. Evidence suggests that genetic variations in any transporter involved in the entry or efflux of platinum drugs alter their kinetics and, to a significant extent, determine patients' responses to them. This review aims to consolidate and describe the major transporters and their polymorphic variants in relation to cisplatin-induced toxicities and resistance in UBC patients. We concluded that the efflux transporters ABCB1, ABCC2, SLC25A21, ATP7A, and the uptake transporter OCT2, as well as the organic anion uptake transporters OAT1 and OAT2, are linked to cisplatin accumulation, toxicity, and resistance in urinary bladder cancer patients. While suppressing the CTR1 gene's expression reduced cisplatin-induced nephrotoxicity and ototoxicity, inhibiting the expression of the MATE1 and MATE2-K genes has been shown to increase cisplatin's nephrotoxicity and resistance. The roles of ABCC5, ABCA8, ABCC10, ABCB10, ABCG1, ATP7B, ABCG2, and mitochondrial SLC25A10 in platinum-receiving urinary bladder cancer patients should be the subject of further investigation.

Leukocyte CH25H is a potential diagnostic and prognostic marker for lung adenocarcinoma

Metastasis, a major challenge during the treatment of lung cancer, causes deterioration in patient health outcomes. Thus, to address this problem, this study aimed to explore the role and contribution of Cholesterol 25-Hydroxylase (CH25H) as a potential diagnostic and prognostic marker in lung cancer. Online public databases were used to analyze the expression level, prognostic value, gene-pathway enrichment, and immune infiltration of CH25H in lung cancer patients. The Real-Time Quantitative Reverse Transcription PCR (qRT-PCR) was used to analyze and detect the CH25H expression levels in leukocytes from lung cancer patients. The expression level of CH25H was significantly reduced in lung adenocarcinoma (LUAD), which is associated with a higher disease stage, but not in lung squamous cell carcinoma (LUSC). Kaplan-Meier survival analysis indicated that LUAD patients with low CH25H expression had a worse prognosis. Mechanistically, our results showed that in LUAD, CH25H may be a regulatory factor affecting the immune cell infiltration level, and the resultant tumor development. Experimental data showed that low expression of CH25H in leukocytes was significantly associated with LUAD metastasis (P < 0.01). Our study suggests that CH25H may function as a prognostic and risk stratification biomarker for LUAD.

Role of cuproptosis-related gene in lung adenocarcinoma

Backgrounds

Lung adenocarcinoma (LUAD) is the most common subtype of lung cancer, which is the leading cause of cancer death. Dysregulation of cell proliferation and death plays a crucial role in the development of LUAD. As of recently, the role of a new form of cell death, cuproptosis, and it has attracted more and more attention. As of yet, it is not clear whether cuproptosis is involved in the progression of LUAD.

Methods

An integrated set of bioinformatics tools was utilized to analyze the expression and prognostic significance of cuproptosis-related genes. Meanwhile, a robust risk signature was developed using machine learning based on prognostic cuproptosis-related genes and explored the value of prognostic cuproptosis-related signature for clinical applications, functional enrichment and immune landscape. Lastly, the dysregulation of the cuproptosis-related genes in LUAD was validated by in vitro experiment.

Results

In this study, first, cuproptosis-related genes were found to be differentially expressed in LUAD patients of public databases, and nine of them had prognostic value. Next, a cuproptosis-related model with five features (DLTA, MTF1, GLS, PDHB and PDHA1) was constructed to separate the patients into high- and low-risk groups based on median risk score. Internal validation set and external validation set were used for model validation and evaluation. What's more, Enrichment analysis of differential genes and the WGCNA identified that cuproptosis-related signatures affected tumor prognosis by influencing tumor immunity. Small molecule compounds were predicted based on differential expressed genes to improve poor prognosis in the high-risk group and a nomogram was constructed to further advance clinical applications. In closing, our data showed that FDX1 affected the prognosis of lung cancer by altering the expression of cuproptosis-related signature.

Conclusion

A new cuproptosis-related signature for survival prediction was constructed and validated by machine learning algorithm and in vitro experiments to reflect tumor immune infiltration in LUAD patients. The purpose of this article was to provide a potential diagnostic and therapeutic strategy for LUAD.

Characterization of a castrate-resistant prostate cancer xenograft derived from a patient of West African ancestry

BACKGROUND

Prostate cancer is a clinically and molecularly heterogeneous disease, with highest incidence and mortality among men of African ancestry. To date, prostate cancer patient-derived xenograft (PCPDX) models to study this disease have been difficult to establish because of limited specimen availability and poor uptake rates in immunodeficient mice. Ancestrally diverse PCPDXs are even more rare, and only six PCPDXs from self-identified African American patients from one institution were recently made available.

METHODS

In the present study, we established a PCPDX from prostate cancer tissue from a patient of estimated 90% West African ancestry with metastatic castration resistant disease, and characterized this model's pathology, karyotype, hotspot mutations, copy number, gene fusions, gene expression, growth rate in normal and castrated mice, therapeutic response, and experimental metastasis.

RESULTS

This PCPDX has a mutation in TP53 and loss of PTEN and RB1. We have documented a 100% take rate in mice after thawing the PCPDX tumor from frozen stock. The PCPDX is castrate- and docetaxel-resistant and cisplatin-sensitive, and has gene expression patterns associated with such drug responses. After tail vein injection, the PCPDX tumor cells can colonize the lungs of mice.

CONCLUSION

This PCPDX, along with others that are established and characterized, will be useful pre-clinically for studying the heterogeneity of prostate cancer biology and testing new therapeutics in models expected to be reflective of the clinical setting.

The AMPK-HOXB9-KRAS axis regulates lung adenocarcinoma growth in response to cellular energy alterations

HOXB9 is an important transcription factor associated with unfavorable outcomes in patients with lung adenocarcinoma (LUAD). However, its degradation mechanism remains unclear. Here, we show that HOXB9 is a substrate of AMP kinase alpha (AMPKα). AMPK mediates HOXB9 T133 phosphorylation and downregulates the level of HOXB9 in mice and LUAD cells. Mechanistically, phosphorylated HOXB9 promoted E3 ligase Praja2-mediated HOXB9 degradation. Blocking HOXB9 phosphorylation by depleting AMPKα1/2 or employing the HOXB9 T133A mutant promoted tumor cell growth in cell culture and mouse xenografts via upregulation of HOXB9 and KRAS that is herein identified as a target of HOXB9. Clinically, AMPK activation levels in LUAD samples were positively correlated with pHOXB9 levels; higher pHOXB9 levels were associated with better survival of patients with LUAD. We thus present a HOXB9 degradation mechanism and demonstrate an AMPK-HOXB9-KRAS axis linking glucose-level-regulated AMPK activation to HOXB9 stability and KRAS gene expression, ultimately controlling LUAD progression.

Excessive activation of HOXB13/PIMREG axis promotes hepatocellular carcinoma progression and drug resistance

The transcription factor HOXB13 is bound up with the occurrence, progression and drug fast of many kinds of cancer. Nevertheless, the specific molecular mechanism of HOXB13 in hepatocellular carcinoma (HCC) is still unknown. This provides an obstacle to the exploration of HCC treatments targeting HOXB13. This study found that HOXB13 was up-regulated in HCC tissues. HOXB13 enhanced the multiplication and metastasis of HCC cells. It enhanced HCC cell drug and anoikis resistance. The analysis of HCC RNA seq data indicated that the expression of HOXB13 and PIMREG were positively correlated. Luciferase report assay showed that HOXB13 could activate PIMREG promoter transcription. The results of RT-qPCR and western blot showed that HOXB13 regulated the transcription of PIMREG. Western blot proved that high expression of PIMREG participated in DNA damage repair and cell cycle regulation by up-regulating RAD51, BRCA1, CDC25A, CDC25B and CDC25C and down-regulating HIPK2. This led to a significant increase in DNA repair capacity, accelerated cell cycle progression, and insensitive to DNA damage. Down-regulation of PIMREG in Hep3B cells overexpressing HOXB13 attenuated the phenotype induced by HOXB13. Therefore, HOXB13 functioned through PIMREG instead of directly regulating the transcription of RAD51, BRCA1, CDC25A, CDC25B and CDC25C. The same results were obtained in vivo. It was concluded that HOXB13 affected the expression of cell cycle and DNA repair related factors by up-regulating the transcription of PIMREG, thereby promoting the progression of HCC and enhancing the resistance of HCC to chemotherapeutics.

[miR-20a-5p inhibits proliferation of lung cancer A549 cells by down-regulating HOXB13]

OBJECTIVE

To investigate the molecular mechanism by which miR-20a-5p regulates HOXB13 gene expression and inhibits lung cancer cell proliferation.

METHODS

The expression levels of HOXB13 mRNA and protein in lung cancer A549 cells transfected with HOXB13 overexpression plasmid or HOXB13 siRNA were detected with real-time fluorescence quantitative PCR (qRT-PCR) and Western blotting. CCK-8 and EdU assays were used to examine the effect of modulation of HOXB13 expression on cell proliferation. We screened possible binding miRNAs of HOXB13 by bioinformatics analysis. In A549 cells transfected with miR-20a-5p mimic or miR-20a-5p inhibitor, the expression level of miR-20a-5p was detected by qRT-PCR and the protein expression of HOXB13 was determined with Western blotting. CCK-8 and EdU assays were used to assess the effect of miR-20a-5p overexpression on the proliferation of A549 cells. miR-20a-5p mimic and HOXB13 overexpression plasmids were co-transfected into A549 cells, and the changes in cell proliferation were evaluated with CCK-8 and EdU assays.

RESULTS

HOXB13 overexpression obviously promoted the proliferation of A549 cells (P < 0.05). miR-20a-5p was identified as the potential binding miRNA of HOXB13. Overexpression of miR-20a-5p in A549 cells significantly decreased the expression of HOXB13 protein (P < 0.05), while interference of miR-20a-5p obviously increased HOXB13 expression (P < 0.05). The results of cell proliferation experiment showed that miR-20a-5p and HOXB13 had opposite effects on cell proliferation, and the cells overexpressing both miR-20a-5p and HOXB13 showed a lower proliferation activity than the cells overexpressing HOXB13 but higher than the cells overexpressing miR-20a-5p alone (P < 0.05).

CONCLUSION

miR-20a-5p inhibits proliferation of lung cancer cells by down-regulating the expression of HOXB13.

LncRNA MAFG-AS1 Promotes Lung Adenocarcinoma Cell Migration and Invasion by Targeting miR-3196 and Regulating SOX12 Expression

Lung adenocarcinoma (LUAD) patients exhibit poor prognosis, primarily due to metastasis. Emerging studies have demonstrated that long noncoding RNAs (lncRNAs) play critical roles in cancer progression and metastasis besides their physiological function. Here, we investigated the potential role of lncRNA MAF BZIP Transcription Factor G Antisense RNA 1 (MAFG-AS1) in LUAD metastasis by analyzing its expression in The Cancer Genome Atlas (TCGA) LUAD database, and its function in LUAD using in vitro and in vivo experiments. We performed bioinformatics analysis, western blotting, dual-luciferase reporter gene assay, RNA immunoprecipitation (RIP), and rescue assays to reveal the molecular mechanisms underlying MAFG-AS1 function. We observed augmented expression of MAFG-AS1 in LUAD tissues compared with normal adjacent tissues, and its association with poor prognosis. Furthermore, MAFG-AS1 overexpression promoted LUAD cell migration, proliferation, invasion, and epithelial mesenchymal transition (EMT). Besides, MAFG-AS1 also targeted miR-3196 directly by acting as an endogenous sponge, thereby rescuing the inhibition of SOX12, a target of miR-3196. Thus, the rescue assays demonstrated that MAFG-AS1 promotes cell migration, invasion, and EMT by modulating the miR-3196/SOX12 pathway. In conclusion, our findings suggest that MAFG-AS1/miR-3196/SOX12 axis regulates LUAD progression and is a potential therapeutic target for LUAD.

Downstream of the HOX genes: explaining conflicting tumour suppressor and oncogenic functions in cancer

The HOX genes are a highly conserved group of transcription factors that have key roles in early development, but which are also highly expressed in most cancers. Many studies have found strong associative relationships between the expression of individual HOX genes in tumours and clinical parameters including survival. For the majority of HOX genes, high tumour expression levels seem to be associated with a worse outcome for patients, and in some cases this has been shown to result from the activation of pro-oncogenic genes and pathways. However, there are also many studies that indicate a tumour suppressor role for some HOX genes, sometimes with conclusions that contradict earlier work. In this review, we have attempted to clarify the role of HOX genes in cancer by focusing on their downstream targets as identified in studies that provide experimental evidence for their activation or repression. On this basis, the majority of HOX genes would appear to have a pro-oncogenic function, with the notable exception of HOXD10, which acts exclusively as a tumour suppressor. HOX proteins regulate a wide range of target genes involved in metastasis, cell death, proliferation, and angiogenesis, and activate key cell signalling pathways. Furthermore, for some functionally related targets, this regulation is achieved by a relatively small subgroup of HOX genes.

Mechanistic Insights Delineating the Role of Cholesterol in Epithelial Mesenchymal Transition and Drug Resistance in Cancer

Despite the significant advancements made in targeted anti-cancer therapy, drug resistance constitutes a multifaceted phenomenon leading to therapy failure and ultimately mortality. Emerging experimental evidence highlight a role of cholesterol metabolism in facilitating drug resistance in cancer. This review aims to describe the role of cholesterol in facilitating multi-drug resistance in cancer. We focus on specific signaling pathways that contribute to drug resistance and the link between these pathways and cholesterol. Additionally, we briefly discuss the molecular mechanisms related to the epithelial-mesenchymal transition (EMT), and the documented link between EMT, metastasis and drug resistance. We illustrate this by specifically focusing on hypoxia and the role it plays in influencing cellular cholesterol content following EMT induction. Finally, we provide a proposed model delineating the crucial role of cholesterol in EMT and discuss whether targeting cholesterol could serve as a novel means of combatting drug resistance in cancer progression and metastasis.

Construction of circRNA-miRNA-mRNA network and identification of novel potential biomarkers for non-small cell lung cancer

Background

The underlying circular RNAs (circRNAs)-related competitive endogenous RNA (ceRNA) mechanisms of pathogenesis and prognosis in non-small cell lung cancer (NSCLC) remain unclear.

Methods

Differentially expressed circRNAs (DECs) in two Gene Expression Omnibus datasets (GSE101684 and GSE112214) were identified by utilizing R package (Limma). Circinteractome and StarBase databases were used to predict circRNA associated-miRNAs and mRNAs, respectively. Then, protein–protein interaction (PPI) network of hub genes and ceRNA network were constructed by STRING and Cytoscape. Also, analyses of functional enrichment, genomic mutation and diagnostic ROC were performed. TIMER database was used to analyze the association between immune infiltration and target genes. Kaplan–Meier analysis, cox regression and the nomogram prediction model were used to evaluate the prognostic value of target genes. Finally, the expression of potential circRNAs and target genes was validated in cell lines and tissues by quantitative real-time PCR (qRT-PCR) and Human Protein Atlas (HPA) database.

Results

In this study, 15 DECs were identified between NSCLC tissues and adjacent-normal tissues in two GEO datasets. Following the qRT-PCR corroboration, 7 DECs (hsa_circ_0002017, hsa_circ_0069244, hsa_circ_026337, hsa_circ_0002346, hsa_circ_0007386, hsa_circ_0008234, hsa_circ_0006857) were dramatically downregulated in A549 and SK-MES-1 compared with HFL-1 cells. Then, 12 circRNA-sponged miRNAs were screened by Circinteractome and StarBase, especially, hsa-miR-767-3p and hsa-miR-767-5p were significantly up-regulated and relevant to the prognosis. Utilizing the miRDB and Cytoscape, 12 miRNA-target genes were found. Functional enrichment, genomic mutation and diagnostic analyses were also performed. Among them, FNBP1, AKT3, HERC1, COL4A1, TOLLIP, ARRB1, FZD4 and PIK3R1 were related to the immune infiltration via TIMER database. The expression of ARRB1, FNBP1, FZD4, and HERC1 was correlated with poor overall survival (OS) in NSCLC patients by cox regression and nomogram. Furthermore, the hub-mRNAs were validated in cell lines and tissues.

Conclusion

We constructed the circRNA-miRNA-mRNA network that might provide novel insights into the pathogenesis of NSCLC and reveal promising immune infiltration and prognostic biomarkers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02278-z.

MiR-495 Inhibits Cisplatin Resistance and Angiogenesis in Esophageal Cancer by Targeting ATP7A

Background: Cancer resistance to chemotherapy is closely associated with changes in transporter systems. In this study, we investigated the possible regulation of 1 copper ion transporter (ATP7A; ATPase copper transporting alpha) by microRNA miR-495 and its implications in cisplatin resistance and angiogenesis in esophageal cancer. Methods: MiR-495 and ATP7A mRNA expression in clinical tissue samples and 2 cancer cell lines (Eca-109 and TE1) were detected by quantitative real-time polymerase chain reaction. The levels of miR-495 and ATP7A expression in Eca-109 and TE1 cells were increased by transfection with miR-495 mimics and ATP7A-overexpression vectors. Cell proliferation, apoptosis, and angiogenesis were assessed by CCK-8, flow cytometry, and tube formation assays, respectively. The levels of TNF-α and VEGF in cell culture supernatants were detected by enzyme linked immunosorbent assay, and in situ expression of NLRP3 was measured by immunofluorescence. The binding of miR-495 to ATP7A sequences was verified by dual luciferase reporter assays. Results:ATP7A expression was significantly increased, while miR-495 expression was decreased in the cancer tissues of esophageal cancer patients. MiR-495 mimics decreased the proliferation and promoted the apoptosis of cisplatin-resistant Eca-109 and TE1 cells. Furthermore, tube formation by human umbilical vein endothelial cells, TNF-α and VEGF secretion, and the levels of MRP1, ABCG1, ABCA1, and NLRP3 expression in cisplatin-resistant Eca-109 and TE1 cells were all reduced by miR-495 mimics. MiR-495 was shown to directly bind to ATP7A gene sequences to repress ATP7A expression in Eca-109 and TE1 cells. ATP7A overexpression substantially abrogated the changes in proliferation, apoptosis, angiogenesis, and above-mentioned gene expression in cisplatin-resistant Eca-109 and TE1 cells. Conclusions: MiR-495 suppressed cisplatin resistance and angiogenesis in esophageal cancer cells by targeting ATP7A gene expression.

Homeobox Genes in Cancers: From Carcinogenesis to Recent Therapeutic Intervention

The homeobox (HOX) genes encoding an evolutionarily highly conserved family of homeodomain-containing transcriptional factors are essential for embryogenesis and tumorigenesis. HOX genes are involved in cell identity determination during early embryonic development and postnatal processes. The deregulation of HOX genes is closely associated with numerous human malignancies, highlighting the indispensable involvement in mortal cancer development. Since most HOX genes behave as oncogenes or tumor suppressors in human cancer, a better comprehension of their upstream regulators and downstream targets contributes to elucidating the function of HOX genes in cancer development. In addition, targeting HOX genes may imply therapeutic potential. Recently, novel therapies such as monoclonal antibodies targeting tyrosine receptor kinases, small molecular chemical inhibitors, and small interfering RNA strategies, are difficult to implement for targeting transcriptional factors on account of the dual function and pleiotropic nature of HOX genes-related molecular networks. This paper summarizes the current state of knowledge on the roles of HOX genes in human cancer and emphasizes the emerging importance of HOX genes as potential therapeutic targets to overcome the limitations of present cancer therapy.

C1GALT1, Negatively Regulated by miR-181d-5p, Promotes Tumor Progression via Upregulating RAC1 in Lung Adenocarcinoma

Glycosyltransferases are frequently dysregulated in lung cancer. Core 1 β 1, 3-galactosyltransferase 1 (C1GALT1), an enzyme highly expressed in various cancers, is correlated with tumor initiation and development. However, the role of C1GALT1 in lung cancer remains poorly understood. In this study, through bioinformatic analysis and clinical validation, we first discovered that C1GALT1 expression was upregulated in lung adenocarcinoma (LUAD) tissues and was closely related to poor prognosis in patients with LUAD. Gain- and loss-of-function experiments showed that C1GALT1 promoted LUAD cell proliferation, migration, and invasion in vitro, as well as tumor formation in vivo. Further investigation demonstrated that RAC1 expression was positively regulated by C1GALT1 in LUAD, whereas silencing Rac1 could reverse C1GALT1-induced tumor growth and metastasis. Moreover, miR-181d-5p was identified as a negative regulator for C1GALT1 in LUAD. As expected, the inhibitory effects of miR-181d-5p on LUAD cell proliferation, migration, and invasion were counteracted by restoration of C1GALT1. In summary, our results highlight the importance of the miR-181d-5p/C1GALT1/RAC1 regulatory axis during LUAD progression. Thus, C1GALT1 may serve as a potential therapeutic target for LUAD.

Connecting Cholesterol Efflux Factors to Lung Cancer Biology and Therapeutics

Cholesterol is a foundational molecule of biology. There is a long-standing interest in understanding how cholesterol metabolism is intertwined with cancer biology. In this review, we focus on the known connections between lung cancer and molecules mediating cholesterol efflux. A major take-home lesson is that the roles of many cholesterol efflux factors remain underexplored. It is our hope that this article would motivate others to investigate how cholesterol efflux factors contribute to lung cancer biology.

Pathogenesis and therapeutic strategy in platinum resistance lung cancer

Platinum compounds (cisplatin and carboplatin) represent the most active anticancer agents in clinical use both of lung cancer in mono-and combination therapies. However, platinum resistance limits its clinical application. It is necessary to understand the molecular mechanism of platinum resistance, identify predictive markers, and develop newer, more effective and less toxic agents to treat platinum resistance in lung cancer. Here, it summarizes the main molecular mechanisms associated with platinum resistance in lung cancer and the development of new approaches to tackle this clinically relevant problem. Moreover, it could lead to the development of more effective treatment for refractory lung cancer in future.

Pharmacological inhibition of noncanonical EED-EZH2 signaling overcomes chemoresistance in prostate cancer

Rationale: Chemoresistance is a major obstacle in prostate cancer (PCa) treatment. We sought to understand the underlying mechanism of PCa chemoresistance and discover new treatments to overcome docetaxel resistance. Methods: We developed a novel phenotypic screening platform for the discovery of specific inhibitors of chemoresistant PCa cells. The mechanism of action of the lead compound was investigated using computational, molecular and cellular approaches. The in vivo toxicity and efficacy of the lead compound were evaluated in clinically-relevant animal models. Results: We identified LG1980 as a lead compound that demonstrates high selectivity and potency against chemoresistant PCa cells. Mechanistically, LG1980 binds embryonic ectoderm development (EED), disrupts the interaction between EED and enhancer of zeste homolog 2 (EZH2), thereby inducing the protein degradation of EZH2 and inhibiting the phosphorylation and activity of EZH2. Consequently, LG1980 targets a survival signaling cascade consisting of signal transducer and activator of transcription 3 (Stat3), S-phase kinase-associated protein 2 (SKP2), ATP binding cassette B 1 (ABCB1) and survivin. As a lead compound, LG1980 is well tolerated in mice and effectively suppresses the in vivo growth of chemoresistant PCa and synergistically enhances the efficacy of docetaxel in xenograft models. Conclusions: These results indicate that pharmacological inhibition of EED-EZH2 interaction is a novel strategy for the treatment of chemoresistant PCa. LG1980 and its analogues have the potential to be integrated into standard of care to improve clinical outcomes in PCa patients.

HOXB13 promotes gastric cancer cell migration and invasion via IGF-1R upregulation and subsequent activation of PI3K/AKT/mTOR signaling pathway

AIMS

This study aimed at exploring HOXB13 expression and function in gastric cancer (GC), and the underlying molecular mechanism.

MATERIALS AND METHODS

HOXB13 and fat mass and obesity-associated protein (FTO) expression in GC and non-GC tissues of GC patients were analyzed using Gene Expression Profiling Interactive Analysis (GEPIA) and verified by quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and western blotting. The regulatory relationship between FTO and HOXB13 was verified via RT-qPCR, methylated RNA immunoprecipitation sequencing (MeRIP-seq), and double luciferase reporter gene assay. The effects of HOXB13 and FTO on proliferation, invasion, and migration of GC cells were studied using EdU and Transwell assays.

KEY FINDINGS

HOXB13 and FTO expression was abnormally high in GC tissues and cell lines, with no significant correlation between HOXB13 and FTO expression and the prognosis of GC patients. Inhibiting FTO expression in GC cells decreased HOXB13 methylation and upregulated HOXB13 expression. Inhibiting HOXB13 and FTO expression suppressed GC cell proliferation, migration, and invasion. Decreased HOXB13 expression suppressed PI3K/AKT/mTOR signaling pathway activity, while atypical HOXB13 expression promoted it. A probable downstream target of HOXB13 was insulin-like growth factor 1 receptor (IGF-1R); a decrease in IGF-1R relieved GC cell migration, invasion, and proliferation and inhibited PI3K/AKT/mTOR signaling pathway activity promoted by atypical HOXB13 expression.

SIGNIFICANCE

HOXB13 and FTO expression is elevated in GC. FTO suppresses HOXB13 methylation; FTO and HOXB13 expression promotes GC cell proliferation, migration, and invasion. HOXB13 expression intensifies GC invasion through PI3K/AKT/mTOR signaling via IGF-1R. HOXB13 and associated signaling pathways can be effective targets for GC therapy.

Deubiquitinase USP35 modulates ferroptosis in lung cancer via targeting ferroportin

BACKGROUND

Ferroptosis is essential to regulate tumor growth and serves as a promising therapeutic target to lung cancer. Ubiquitin-specific protease 35 (USP35) belongs to the deubiquitinases family that is associated with cell proliferation and mitosis. In this research, we aim to elucidate the potential role and molecular basis of USP35 in lung cancer.

METHODS

Lung cancer cells were infected with lentiviral vectors to silence or overexpress USP35. Cell viability, colony formation, lipid reactive oxygen species production, intracellular iron metabolism, and other ferroptotic markers were detected. The role of USP35 on ferroptosis and tumor progression were also tested in mouse tumor xenograft models in vivo.

RESULTS

USP35 was abundant in human lung cancer tissues and cell lines. USP35 knockdown promoted ferroptosis, and inhibited cell growth, colony formation, and tumor progression in lung cancer cells. USP35 overexpression did not affect tumorigenesis and ferroptosis under basal conditions, but reduced erastin/RSL3-triggered iron disturbance and ferroptosis, thereby facilitating lung cancer cell growth and tumor progression. Further studies determined that USP35 directly interacted with ferroportin (FPN) and functioned as a deubiquitinase to maintain its protein stability. More importantly, we observed that USP35 knockdown sensitized lung cancer cells to cisplatin and paclitaxel chemotherapy.

CONCLUSION

USP35 modulates ferroptosis in lung cancer via targeting FPN, and it is a promising therapeutic target to lung cancer.

Employing siRNA tool and its delivery platforms in suppressing cisplatin resistance: Approaching to a new era of cancer chemotherapy

Although chemotherapy is a first option in treatment of cancer patients, drug resistance has led to its failure, requiring strategies to overcome it. Cancer cells are capable of switching among molecular pathways to ensure their proliferation and metastasis, leading to their resistance to chemotherapy. The molecular pathways and mechanisms that are responsible for cancer progression and growth, can be negatively affected for providing chemosensitivity. Small interfering RNA (siRNA) is a powerful tool extensively applied in cancer therapy in both pre-clinical (in vitro and in vivo) and clinical studies because of its potential in suppressing tumor-promoting factors. As such oncogene pathways account for cisplatin (CP) resistance, their targeting by siRNA plays an important role in reversing chemoresistance. In the present review, application of siRNA for suppressing CP resistance is discussed. The first priority of using siRNA is sensitizing cancer cells to CP-mediated apoptosis via down-regulating survivin, ATG7, Bcl-2, Bcl-xl, and XIAP. The cancer stem cell properties and related molecular pathways including ID1, Oct-4 and nanog are inhibited by siRNA in CP sensitivity. Cell cycle arrest and enhanced accumulation of CP in cancer cells can be obtained using siRNA. In overcoming siRNA challenges such as off-targeting feature and degradation, carriers including nanoparticles and biological carriers have been applied. These carriers are important in enhancing cellular accumulation of siRNA, elevating gene silencing efficacy and reversing CP resistance.

The deubiquitinase USP11 regulates cell proliferation and ferroptotic cell death via stabilization of NRF2 USP11 deubiquitinates and stabilizes NRF2

The transcription factor nuclear factor (erythroid-derived 2)-like 2 (NRF2) plays a key role in cancer progression and is tightly regulated by the proteasome pathway. E3 ligases that mediate NRF2 ubiquitination have been widely reported, but the mechanism of NRF2 deubiquitination remains largely unclear. Here, we identified ubiquitin-specific-processing protease 11 (USP11) in NRF2 complexes and confirmed an interaction between these two proteins. We further found that USP11 deubiquitinates NRF2; this modification stabilizes NRF2. Functionally, USP11 depletion contributes to the suppression of cell proliferation and induction of ferroptotic cell death due to ROS-mediated stress, which can be largely abrogated by overexpression of NRF2. Finally, immunohistochemical staining of USP11 and NRF2 was performed using a lung tissue microarray, which revealed that USP11 is highly expressed in patients with NSCLC and positively correlated with NRF2 expression. Together, USP11 stabilizes NRF2 and is thus an important player in cell proliferation and ferroptosis.

Multiple roles of HOX proteins in Metastasis: Let me count the ways

Knowledge of the role of HOX proteins in cancer has been steadily accumulating in the last 25 years. They are encoded by 39 HOX genes arranged in 4 distinct clusters, and have unique and redundant function in all types of cancers. Many HOX genes behave as oncogenic transcriptional factors regulating multiple pathways that are critical to malignant progression in a variety of tumors. Some HOX proteins have dual roles that are tumor-site specific, displaying both oncogenic and tumor suppressor function. The focus of this review is on how HOX proteins contribute to growth or suppression of metastasis. The review will cover HOX protein function in the critical aspects of epithelial-mesenchymal transition, in cancer stem cell sustenance and in therapy resistance, manifested as distant metastasis. The emerging role of adiposity in both initiation and progression of metastasis is described. Defining the role of HOX genes in the metastatic process has identified candidates for targeted cancer therapies that may combat the metastatic process. We will discuss potential therapeutic opportunities, particularly in pathways influenced by HOX proteins.

Roles of the HOX Proteins in Cancer Invasion and Metastasis

Invasion and metastasis correspond to the foremost cause of cancer-related death, and the molecular networks behind these two processes are extremely complex and dependent on the intra- and extracellular conditions along with the prime of the premetastatic niche. Currently, several studies suggest an association between the levels of HOX genes expression and cancer cell invasion and metastasis, which favour the formation of novel tumour masses. The deregulation of HOX genes by HMGA2/TET1 signalling and the regulatory effect of noncoding RNAs generated by the HOX loci can also promote invasion and metastasis, interfering with the expression of HOX genes or other genes relevant to these processes. In this review, we present five molecular mechanisms of HOX deregulation by which the HOX clusters products may affect invasion and metastatic processes in solid tumours.

Decreased expression of JAK1 associated with immune infiltration and poor prognosis in lung adenocarcinoma

Janus kinase 1 (JAK1) is a member of the JAK family, which plays an essential and non-redundant role in tumorigenesis. However, the potential role of JAK1 in immune infiltration and prognosis of lung adenocarcinoma (LUAD) remains unclear. The mRNA expression and methylation level of JAK1 in LUAD were examined using the Oncomine and The Cancer Genome Atlas (TCGA) databases, respectively. The correlations between JAK1 expression and its methylation level and clinicopathological parameters were analyzed. The Kaplan–Meier plotter database was used to evaluate the prognostic value of JAK1 in LUAD. The signaling pathways associated with JAK1 expression were identified by performing a GSEA. The CIBERSORT and TIMER databases were used to analyze the correlations between JAK1 and tumor-infiltrating immune cells. In addition, the JAK1 expression and proportion of immune cells in LUAD cell lines were analyzed. The JAK1 expression was remarkably decreased in patients with LUAD and significantly correlated with the clinical features of patients with LUAD. The JAK1 methylation level was increased and negatively correlated with its mRNA expression. A decrease in JAK1 expression was correlated with poor prognosis. The results of GSEA showed that cell adhesion, tumorigenesis, and immune-related signaling pathways were mainly enriched. JAK1 was positively associated with tumor-infiltrating immune cells, and the results of CIBERSORT analysis suggested that JAK1 was correlated with monotypes and M1 macrophages. The results of the TIMER database analysis confirmed that JAK1 was closely associated with the gene markers of M1 macrophages. Thus, JAK1 may serve as a potential prognostic biomarker in LUAD and is associated with immune infiltration.

DNA Repair-Based Gene Expression Signature and Distinct Molecular Subtypes for Prediction of Clinical Outcomes in Lung Adenocarcinoma

Objective: To conduct a robust prognostic gene expression signature and characterize molecular subtypes with distinct clinical characteristics for lung adenocarcinoma (LUAD).

Methods: Based on DNA repair genes from the GSEA database, a prognostic signature was conducted in the TCGA-LUAD training set via univariate and multivariate cox regression analysis. Its prediction power was validated by overall survival analysis, relative operating characteristic (ROC) curves and stratification analysis in the GSE72094 verification set. Involved pathways in the high- and low-risk groups were analyzed by GSEA. A nomogram was built based on the signature and clinical features and its performance was assessed by calibration plots. LUAD samples were clustered via the ConsensusClusterPlus package. The differences in clinical outcomes, single nucleotide polymorphism (SNP) and sensitivity to chemotherapy drugs between molecular subtypes were analyzed.

Results: A 13-DNA repair gene-signature was constructed for LUAD prognosis. Following validation, it can robustly and independently predict patients' clinical outcomes. The GSEA results exhibited the differences in pathways between high- and low- risk groups. A nomogram combining the signature and stage could accurately predict 1-, 3-, and 5-year survival probability. Two distinct molecular subtypes were characterized based on DNA repair genes. Patients in the Cluster 2 exhibited a worse prognosis and were more sensitive to common chemotherapy than those in the Cluster 1.

Conclusion:This study proposed a 13-DNA repair gene-signature as a prognostic factor for LUAD patients, which can independently predict clinical outcomes by complement of the stage. Moreover, we characterized two LUAD subtypes with distinct clinical outcomes, somatic gene mutations, and drug sensitivity in cancer based on DNA repair genes.

Prognostic Value of EZH2 in Non-Small-Cell Lung Cancers: A Meta-Analysis and Bioinformatics Analysis

Background

The prognosis of non-small-cell lung cancer (NSCLC) has not been significantly improved. In the past several years, research on epigenetics is in full swing. There is a focus on the gene EZH2; however, its role as a predictor of the prognosis of NSCLC is in the debate.

Objective

To clarify if the expression level of EZH2 can influence the prognosis of NSCLC and explain its prognostic value.

Methods

We have systematically searched PubMed, Web of Science, and Cochrane library, screened relevant articles, and conducted a meta-analysis on the expression level of EZH2 in NSCLC. We collected the hazard ratio (HR) and the 95% confidence interval (CI) and used STATA 12.0 to calculate the combined result of EZH2 overall survival. In addition, we conducted subgroup analyses, a sensitivity analysis, and a funnel plot to test the reliability of the results. We further validated these meta-analysis results using the Kaplan-Meier plotter database and The Cancer Genome Atlas (TCGA) database. In addition, we have investigated the correlation between EZH2 expression and EGFR expression, KRAS expression, BRAF expression, and smoking in TCGA database to further explore the mechanism behind the influence of high EZH2 expression on lung cancer prognosis.

Results

13 studies including 2180 participants were included in the meta-analysis. We found that high expression of EZH2 indicates a poor prognosis of NSCLC (HR = 1.65 and 95% CI 1.16-2.35; p ≤ 0.001). Subgroup analyses showed high heterogeneity in stages I-IV (I ² = 85.1% and p ≤ 0.001) and stages I-III (I ² = 66.9% and p = 0.029) but not in stage I (I ² = 0.00% and p = 0.589). In the Kaplan-Meier plotter database, there was a high expression in 963 cases and low expression in 964 cases (HR = 1.31 and 95% CI 1.15-1.48; p < 0.05). Further analysis found that the high expression of EZH2 was statistically significant in lung adenocarcinoma (HR = 1.27and 95% CI 1.01-1.6; p = 0.045), but not in lung squamous cell carcinoma (HR = 1.03 and 95% CI 0.81-1.3; p = 0.820). The results of the TCGA database showed that the expression of EZH2 in normal tissues was lower than that in lung cancer tissues (p < 0.05). Smoking was associated with high expression of EZH2 (p < 0.001). EZH2 was also highly expressed in lung cancers with positive KRAS expression, and the correlation was positive in lung adenocarcinoma (r = 0.3129 and p < 0.001). The correlation was also positive in lung squamous cell carcinoma (r = 0.3567 and p < 0.001). EZH2 expression was positively correlated with BRAF expression (r = 0.2397 and p < 0.001), especially in lung squamous cell carcinoma (r = 0.3662 and p < 0.001). In lung squamous cell carcinoma, a positive yet weak correlation was observed between EZH2 expression and EGFR expression (r = 0.1122 and p < 0.001).

Conclusions

The high expression of EZH2 indicates a poor prognosis of NSCLC, which may be related to tumor stage or cancer type. EZH2 may be an independent prognostic factor for NSCLC. EZH2 high expression or its synergistic action with KRAS and BRAF mutations affects the prognosis of non-small-cell lung cancer.

LncRNA SNHG14 regulates the DDP-resistance of non-small cell lung cancer cell through miR-133a/HOXB13 pathway

Background

Recently, long non-coding RNAs (lncRNAs) have been reported to be involved in regulating chemo-resistance of NSCLC, however, the role of lncRNA SNHG14 in the DDP-resistance of NSCLC remains unexplored.

Methods

Relative expression of SNHG14, HOXB13 and miR-133a in DDP-resistant A549 (A549/DDP) cell and its parental cell A549 were measured using qRT-PCR. Cell proliferation viability of indicated A549/DDP cell was estimated via CCK-8 and colony formation experiments. Cell cycle and apoptosis were analyzed through flow cytometry. Expression of apoptosis-related protein and HOXB13 were detected via western blot. The interaction among SNHG14, HOXB13 and miR-133a was predicted by bioinformatics and validated by dual-luciferase reporter assay.

Results

LncRNA SNHG14 and HOXB13 were upregulated while miR-133a was downregulated in A549/DDP cell line compared to A549 cell line. SNHG14 knockdown or miR-133a overexpression was demonstrated to increase the DDP-sensitivity of A549/DDP cells. SNHG14 was revealed to compete with HOXB13 for miR-133a binding in A549/DDP cells. Inhibition of miR-133a in A549 cells could reverse the promotive effects of SNHG14 knockdown on DDP-sensitivity, as well as the inhibitory effects on HOXB13 expression. HOXB13 overexpression was revealed to abolish the enhanced effects of miR-133a on the sensitivity of A549/DDP cell to DDP.

Conclusion

Our findings demonstrated that SNHG14 was involved in the development of DDP-resistance of A549/DDP cells through miR-133a/HOXB13 axis, which may present a path to novel therapeutic stratagems for DDP resistance of NSCLC.

Long non-coding RNA CASC9 promotes gefitinib resistance in NSCLC by epigenetic repression of DUSP1

Resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib, has greatly affected clinical outcomes in non-small cell lung cancer (NSCLC) patients. The long noncoding RNAs (lncRNAs) are known to regulate tumorigenesis and cancer progression, but their contributions to NSCLC gefitinib resistance remain poorly understood. In this study, by analyzing the differentially expressed lncRNAs in gefitinib-resistant cells and gefitinib-sensitive cells in the National Institute of Health GEO dataset, we found that lncRNA CASC9 expression was upregulated, and this was also verified in resistant tissues. Gain and loss of function studies showed that CASC9 inhibition restored gefitinib sensitivity both in vitro and in vivo, whereas CASC9 overexpression promoted gefitinib resistance. Mechanistically, CASC9 repressed the tumor suppressor DUSP1 by recruiting histone methyltransferase EZH2, thereby increasing the resistance to gefitinib. Furthermore, ectopic expression of DUSP1 increased gefitinib sensitivity by inactivating the ERK pathway. Our results highlight the essential role of CASC9 in gefitinib resistance, suggesting that the CASC9/EZH2/DUSP1 axis might be a novel target for overcoming EGFR-TKI resistance in NSCLC.

Hydrogen Peroxide Causes Cell Death via Increased Transcription of HOXB13 in Human Lung Epithelial A549 Cells

Although homeobox protein B13 (HOXB13) is an oncogenic transcription factor, its role in stress response has rarely been examined. We previously reported that knockdown of HOXB13 reduces the cytotoxicity caused by various oxidative stress inducers. Here, we studied the role of HOXB13 in cytotoxicity caused by hydrogen peroxide in human lung epithelial A549 cells. The knockdown of HOXB13 reduced hydrogen peroxide-induced cytotoxicity; however, this phenomenon was largely absent in the presence of antioxidants (Trolox or N-acetyl cysteine (NAC)). This suggests that HOXB13 may be involved in the cytotoxicity caused by hydrogen peroxide via the production of reactive oxygen species (ROS). Hydrogen peroxide also increased both the mRNA and protein levels of HOXB13. However, these increases were rarely observed in the presence of a transcriptional inhibitor, which suggests that hydrogen peroxide increases protein levels via increased transcription of HOXB13. Furthermore, cell death occurred in A549 cells that highly expressed HOXB13. However, this cell death was mostly inhibited by treatment with antioxidants. Taken together, our findings indicate that HOXB13 may be a novel factor involved in the induction of oxidative stress, which causes cell death via intracellular ROS production.

miR-140-3p enhances cisplatin sensitivity and attenuates stem cell-like properties through repressing Wnt/β-catenin signaling in lung adenocarcinoma cells

Lung adenocarcinoma (LUAD) is the most predominant subtype of non-small cell lung cancer (NSCLC) that is experiencing the fastest growth rate in incidence. Chemoresistance and the presence of cancer stem cells are considered to be the main obstacles preventing the successful treatment of patients with NSCLC, the molecular mechanism of which remains poorly understood. The present study aimed to investigate the effects of microRNA (miR)-140-3p on cisplatin sensitivity and stem cell-like properties of LUAD cells. Analysis of publicly available data demonstrated that miR-140-3p expression was downregulated in LUAD, and positively associated with the overall survival rate of patients. In addition, transfection with the miR-140-3p mimic reduced LUAD cell viability and induced apoptosis following treatment with cisplatin whilst decreasing stem cell-like properties. miR-140-3p overexpression was also found to attenuate cisplatin resistance and reduce stem cell-like properties in LUAD cells by suppressing Wnt/β-catenin signaling, all of which were reversed by the overexpression of β-catenin. Taken together, results of the present study suggest miR-140-3p to be an effective therapeutic strategy for patients with LUAD.

Quantitative Analysis of Differential Expression of HOX Genes in Multiple Cancers

Transcription factors encoded by Homeobox (HOX) genes play numerous key functions during early embryonic development and differentiation. Multiple reports have shown that mis-regulation of HOX gene expression plays key roles in the development of cancers. Their expression levels in cancers tend to differ based on tissue and tumor type. Here, we performed a comprehensive analysis comparing HOX gene expression in different cancer types, obtained from The Cancer Genome Atlas (TCGA), with matched healthy tissues, obtained from Genotype-Tissue Expression (GTEx). We identified and quantified differential expression patterns that confirmed previously identified expression changes and highlighted new differential expression signatures. We discovered differential expression patterns that are in line with patient survival data. This comprehensive and quantitative analysis provides a global picture of HOX genes' differential expression patterns in different cancer types.

HOXB13 controls cell state through super-enhancers

Expression of the homeodomain transcription factor HOXB13 has been demonstrated in several malignancies but its role in tumorigenesis remains elusive. We observed high levels of HOXB13 in poorly differentiated pediatric tumors including a highly aggressive childhood neoplasm - malignant rhabdoid tumor. In a xenograft model of rhabdoid tumor, knockout of HOXB13 diminished tumor growth while partial knockdown of HOXB13 promoted differentiation of tumor cells into bone. These results suggest that HOXB13 enhances rhabdoid malignancy by interfering with mesenchymal stem cell differentiation. Consistent with this hypothesis, overexpression of HOXB13 in mesenchymal progenitor cells inhibited adipogenic, myogenic, and osteogenic differentiation. Mechanistically, we demonstrated that HOXB13 binds to super-enhancer regions regulating genes involved in differentiation and tumorigenesis.

Osteopontin Mediates Cetuximab Resistance via the MAPK Pathway in NSCLC Cells

Background

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. The high expression of osteopontin (OPN) is an important factor that aggravates drug resistance and causes a poor prognosis in this disease. Therefore, understanding the molecular mechanism of OPN is critical for the treatment and prognosis of NSCLC.

Methods

We used bioinformatics analysis to verify the expression of OPN in normal lung tissues and lung cancer tissues. Then we overexpressed and knocked down OPN in cell lines to detect cell proliferation, migration, invasion, and effects on signaling pathways. Finally, malignant progression and drug resistance induced by OPN were investigated by the wound healing assay, transwell assay, clone formation assay, and Western blot analysis.

Results

We verified that OPN was upregulated in NSCLC tissues, and its overexpression induced NSCLC cell proliferation, migration, and invasion via the mitogen-activated protein kinase (MAPK) pathway. Furthermore, overexpression of OPN reduced the sensitivity of NSCLC cells to cetuximab by upregulating MAPK pathway-related proteins. These results suggested that OPN promoted malignant progression and mediated drug resistance via the MAPK signaling pathway in NSCLC cells.

Conclusion

This study reveals the important role of OPN in NSCLC cells, making it a potential target for improving chemotherapy efficiency in patients with NSCLC.

HOX family transcription factors: Related signaling pathways and post-translational modifications in cancer

HOX family transcription factors belong to a highly conserved subgroup of the homeobox superfamily that determines cellular fates in embryonic morphogenesis and the maintenance of adult tissue architecture. HOX family transcription factors play key roles in numerous cellular processes including cell growth, differentiation, apoptosis, motility, and angiogenesis. As tumor promoters or suppressors HOX family members have been reported to be closely related with a variety of cancers. They closely regulate tumor initiation and growth, invasion and metastasis, angiogenesis, anti-cancer drug resistance and stem cell origin. Here, we firstly described the pivotal roles of HOX transcription factors in tumorigenesis. Then, we summarized the main signaling pathways regulated by HOX transcription factors, including Wnt/β-catenin, transforming growth factor β, mitogen-activated protein kinase, phosphoinositide 3-kinase/Akt, and nuclear factor-κB signalings. Finally, we outlined the important post-translational modifications of HOX transcription factors and their regulation in cancers. Future research directions on the HOX transcription factors are also discussed.