Wnt signaling as potential therapeutic target in lung cancer

IC Regimen: Delaying Resistance to Lorlatinib in ALK Driven Cancers by Adding Repurposed Itraconazole and Cilostazol

Lorlatinib is a pharmaceutical ALK kinase inhibitor used to treat ALK driven non-small cell lung cancers. This paper analyses the intersection of past published data on the physiological consequences of two unrelated drugs from general medical practice-itraconazole and cilostazol-with the pathophysiology of ALK positive non-small cell lung cancer. A conclusion from that data analysis is that adding itraconazole and cilostazol may make lorlatinib more effective. Itraconazole, although marketed worldwide as a generic antifungal drug, also inhibits Hedgehog signaling, Wnt signaling, hepatic CYP3A4, and the p-gp efflux pump. Cilostazol, marketed worldwide as a generic thrombosis preventative drug, acts by inhibiting phosphodiesterase 3, and, by so doing, lowers platelets' adhesion, thereby partially depriving malignant cells of the many tumor trophic growth factors supplied by platelets. Itraconazole may enhance lorlatinib effectiveness by (i) reducing or stopping a Hedgehog-ALK amplifying feedback loop, by (ii) increasing lorlatinib's brain levels by p-gp inhibition, and by (iii) inhibiting growth drive from Wnt signaling. Cilostazol, surprisingly, carries minimal bleeding risk, lower than that of aspirin. Risk/benefit assessment of the combination of metastatic ALK positive lung cancer being a low-survival disease with the predicted safety of itraconazole-cilostazol augmentation of lorlatinib favors a trial of this drug trio in ALK positive lung cancer.

The oncogenic role of LGR6 overexpression induced by aberrant Wnt/β-catenin signaling in lung cancer

BACKGROUND

Molecular abnormalities in the Wnt/β-catenin pathway confer malignant phenotypes in lung cancer. Previously, we identified the association of leucine-rich repeat-containing G protein-coupled receptor 6 (LGR6) with oncogenic Wnt signaling, and its downregulation upon β-catenin knockdown in non-small cell lung cancer (NSCLC) cells carrying CTNNB1 mutations. The aim of this study was to explore the mechanisms underlying this association and the accompanying phenotypes.

METHODS

LGR6 expression in lung cancer cell lines and surgical specimens was analyzed using quantitative RT-PCR and immunohistochemistry. Cell growth was assessed using colony formation assay. Additionally, mRNA sequencing was performed to compare the expression profiles of cells subjected to different treatments.

RESULTS

LGR6 was overexpressed in small cell lung cancer (SCLC) and NSCLC cell lines, including the CTNNB1-mutated NSCLC cell lines HCC15 and A427. In both cell lines, LGR6 knockdown inhibited cell growth. LGR6 expression was upregulated in spheroids compared to adherent cultures of A427 cells, suggesting that LGR6 participates in the acquisition of cancer stem cell properties. Immunohistochemical analysis of lung cancer specimens revealed that the LGR6 protein was predominantly overexpressed in SCLCs, large cell neuroendocrine carcinomas, and lung adenocarcinomas, wherein LGR6 overexpression was associated with vascular invasion, the wild-type EGFR genotype, and an unfavorable prognosis. Integrated mRNA sequencing analysis of HCC15 and A427 cells with or without LGR6 knockdown revealed LGR6-related pathways and genes associated with cancer development and stemness properties.

CONCLUSIONS

Our findings highlight the oncogenic roles of LGR6 overexpression induced by aberrant Wnt/β-catenin signaling in lung cancer.

FOXN Transcription Factors: Regulation and Significant Role in Cancer

A growing number of studies have demonstrated that cancer development is closely linked to abnormal gene expression, including alterations in the transcriptional activity of transcription factors. The Forkhead box class N (FOXN) proteins FOXN1-6 form a highly conserved class of transcription factors, which have been shown in recent years to be involved in the regulation of malignant progression in a variety of cancers. FOXNs mediate cell proliferation, cell-cycle progression, cell differentiation, metabolic homeostasis, embryonic development, DNA damage repair, tumor angiogenesis, and other critical biological processes. Therefore, transcriptional dysregulation of FOXNs can directly affect cellular physiology and promote cancer development. Numerous studies have demonstrated that the transcriptional activity of FOXNs is regulated by protein-protein interactions, microRNAs (miRNA), and posttranslational modifications (PTM). However, the mechanisms underlying the molecular regulation of FOXNs in cancer development are unclear. Here, we reviewed the molecular regulatory mechanisms of FOXNs expression and activity, their role in the malignant progression of tumors, and their value for clinical applications in cancer therapy. This review may help design experimental studies involving FOXN transcription factors, and enhance their therapeutic potential as antitumor targets.

The RNA-binding protein PCBP1 represses lung adenocarcinoma progression by stabilizing DKK1 mRNA and subsequently downregulating β-catenin

Background

PolyC-RNA-binding protein 1 (PCBP1) functions as a tumour suppressor and RNA regulator that is downregulated in human cancers. Here, we aimed to reveal the biological function of PCBP1 in lung adenocarcinoma (LUAD).

Methods

First, PCBP1 was identified as an important biomarker that maintains LUAD through The Cancer Genome Atlas (TCGA) project screening and confirmed by immunohistochemistry and qPCR. Via colony formation, CCK8, IncuCyte cell proliferation, wound healing and Transwell assays, we confirmed that PCBP1 was closely related to the proliferation and migration of LUAD cells. The downstream gene DKK1 was discovered by RNA sequencing of PCBP1 knockdown cells. The underlying mechanisms were further investigated using western blot, qPCR, RIP, RNA pulldown and mRNA stability assays.

Results

We demonstrate that PCBP1 is downregulated in LUAD tumour tissues. The reduction in PCBP1 promotes the proliferation, migration and invasion of LUAD in vitro and in vivo. Mechanistically, the RNA-binding protein PCBP1 represses LUAD by stabilizing DKK1 mRNA. Subsequently, decreased expression of the DKK1 protein relieves the inhibitory effect on the Wnt/β-catenin signalling pathway. Taken together, these results show that PCBP1 acts as a tumour suppressor gene, inhibiting the tumorigenesis of LUAD.

Conclusions

We found that PCBP1 inhibits LUAD development by upregulating DKK1 to inactivate the Wnt/β-catenin pathway. Our findings highlight the potential of PCBP1 as a promising therapeutic target.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03552-y.

Lung Cancer Stem Cell Markers as Therapeutic Targets: An Update on Signaling Pathways and Therapies

Cancer stem cells, a relatively small group of self-renewing cancer cells, were first isolated from acute myeloid leukemia. These cells can play a crucial role in tumor metastasis, relapse, and therapy resistance. The cancer stem cell theory may be applied to lung cancer and explain the inefficiency of traditional treatments and eventual recurrence. However, because of the unclear accuracy and illusive biological function of cancer stem cells, some researchers remain cautious about this theory. Despite the ongoing controversy, cancer stem cells are still being investigated, and their biomarkers are being discovered for application in cancer diagnosis, targeted therapy, and prognosis prediction. Potential lung cancer stem cell markers mainly include surface biomarkers such as CD44, CD133, epithelial cell adhesion molecule, and ATP-binding cassette subfamily G member 2, along with intracellular biomarkers such as aldehyde dehydrogenase, sex-determining region Y-box 2, NANOG, and octamer-binding transcription factor 4. These markers have different structures and functions but are closely associated with the stem potential and uncontrollable proliferation of tumor cells. The aberrant activation of major signaling pathways, such as Notch, Hedgehog, and Wnt, may be associated with the expression and regulation of certain lung cancer stem cell markers, thus leading to lung cancer stem cell maintenance, chemotherapy resistance, and cancer promotion. Treatments targeting lung cancer stem cell markers, including antibody drugs, nanoparticle drugs, chimeric antigen receptor T-cell therapy, and other natural or synthetic specific inhibitors, may provide new hope for patients who are resistant to conventional lung cancer therapies. This review provides comprehensive and updated data on lung cancer stem cell markers with regard to their structures, functions, signaling pathways, and promising therapeutic target approaches, aiming to elucidate potential new therapies for lung cancer.

The cancer/testis antigen HORMAD1 mediates epithelial-mesenchymal transition to promote tumor growth and metastasis by activating the Wnt/β-catenin signaling pathway in lung cancer

The cancer/testis antigen HORMAD1 is a mechanical regulator that modulates DNA homologous recombination repair and mismatch repair in multiple cancers. However, the role and underlying regulatory mechanisms of HORMAD1 in lung cancer progression remain unknown. Here, we show that HORMAD1 is upregulated in lung adenocarcinoma tissues compared with adjacent normal tissues and that aberrant HORMAD1 expression predicts poor prognosis. We further demonstrate that HORMAD1 promotes the proliferation, migration and invasion of lung cancer cells both in vitro and in vivo by inducing epithelial-mesenchymal transition (EMT). Subsequent mechanistic investigations revealed that HORMAD1 activates the Wnt/β-catenin pathway by increasing the phosphorylation level of AKT at Ser473 and that of GSK-3β at Ser9 in lung cancer cells, which decreases the phosphorylation level of β-catenin at Ser33/37/Thr41, enhances the cytoplasmic and nuclear accumulation of β-catenin and its transcriptional activity, consequently promoting EMT and lung cancer growth and metastasis. Our results provide new insights into the functional role and regulatory mechanism of HORMAD1 in lung cancer progression and identify HORMAD1 as a promising prognostic biomarker and therapeutic target for lung cancer.

miR-377-3p-Mediated EGR1 Downregulation Promotes B[a]P-Induced Lung Tumorigenesis by Wnt/Beta-Catenin Transduction

Polycyclic aromatic hydrocarbons (PAHs), particularly benzo[a]pyrene (B[a]P), found in cigarette smoke and air pollution, is an important carcinogen. Nevertheless, early molecular events and related regulatory effects of B[a]P-mediated cell transformation and tumor initiation remain unclear. This study found that EGR1 was significantly downregulated during human bronchial epithelial cell transformation and mice lung carcinogenesis upon exposure to B[a]P and its active form BPDE, respectively. In contrast, overexpression of EGR1 inhibited the BPDE-induced cell malignant transformation. Moreover, miR-377-3p was strongly enhanced by BPDE/B[a]P exposure and crucial for the inhibition of EGR1 expression by targeting the 3'UTR of EGR1. MiR-377-3p antagomir reversed the effect of EGR1 downregulation in cell malignant transformation and tumor initiation models. Furthermore, the B[a]P-induced molecular changes were evaluated by IHC in clinical lung cancer tissues and examined with a clinic database. Mechanistically, EGR1 inhibition was also involved in the regulation of Wnt/β-catenin transduction, promoting lung tumorigenesis following B[a]P/BPDE exposure. Taken together, the results demonstrated that bBenzo[a]pyrene exposure might induce lung tumorigenesis through miR-377-3p-mediated reduction of EGR1 expression, suggesting an important role of EGR1 in PAHs-induced lung carcinogenesis.

Targeting Signaling Pathway Networks in Several Malignant Tumors: Progresses and Challenges

Malignant tumors remain the health problem of highest concern among people worldwide due to its high mortality and recurrence. Lung, gastric, liver, colon, and breast cancers are among the top five malignant tumors in terms of morbidity and mortality. In cancer biology, aberrant signaling pathway regulation is a prevalent theme that drives the generation, metastasis, invasion, and other processes of all malignant tumors. The Wnt/β-catenin, PI3K/AKT/mTOR, Notch and NF-kB pathways are widely concerned and signal crosstalks exist in the five solid tumors. This review provides an innovative summary of the recent progress in research on these signaling pathways, the underlying mechanism of the molecules involved in these pathways, and the important role of some miRNAs in tumor-related signaling pathways. It also presents a brief review of the antitumor molecular drugs that target these signaling pathways. This review may provide a theoretical basis for the study of the molecular biological mechanism of malignant tumors and vital information for the development of new treatment strategies with a focus on efficacy and the reduction of side effects.

Computational Analysis of Drug Resistance Network in Lung Adenocarcinoma

BACKGROUND

Lung cancer is a significant health problem and accounts for one-third of the deaths worldwide. A great majority of these deaths are caused by non-small cell lung cancer (NSCLC). Chemotherapy is the leading treatment method for NSCLC, but resistance to chemotherapeutics is an important limiting factor that reduces the treatment success of patients with NSCLC.

OBJECTIVE

In this study, the relationship between differentially expressed genes affecting the survival of the patients, according to the bioinformatics analyses, and the mechanism of drug resistance is investigated for non-small cell lung adenocarcinoma patients.

METHODS

Five hundred thirteen patient samples were compared with fifty-nine control samples. The employed dataset was downloaded from The Cancer Genome Atlas (TCGA) database. The information on how the drug activity altered against the expressional diversification of the genes was extracted from the NCI-60 database. Four hundred thirty-three drugs with known mechanism of action (MoA) were analyzed. Diversifications of the activity of these drugs related to genes were considered based on nine lung cancer cell lines virtually. The analyses were performed using R programming language, GDCRNATools, rcellminer, and Cytoscape.

RESULTS

This work analyzed the common signaling pathways and expressional alterations of the proteins in these pathways associated with survival and drug resistance in lung adenocarcinoma. Deduced computational data demonstrated that proteins of EGFR, JNK/MAPK, NF-κB, PI3K /AKT/mTOR, JAK/STAT, and Wnt signaling pathways were associated with molecular mechanism of resistance to anticancer drugs in NSCLC cells.

CONCLUSION

To understand the relationships between resistance to anticancer drugs and EGFR, JNK/MAPK, NF-κB, PI3K /AKT/mTOR, JAK/STAT, and Wnt signaling pathways is an important approach to design effective therapeutics for individuals with NSCLC adenocarcinoma.

TIPE3 promotes non-small cell lung cancer progression via the protein kinase B/extracellular signal-regulated kinase 1/2-glycogen synthase kinase 3β-β-catenin/Snail axis

Background

Tumor necrosis factor-α-induced protein 8-like 3 (TNFAIP8L3, also called TIPE3) has been shown to activate PI3K-AKT and MEK-ERK pathways. However, the roles of TIPE3 in progression of lung cancer are largely unknown.

Methods

Immunohistochemistry and western blotting were carried out to analyze the expression of TIPE3 in lung cancer clinical tissues and cells. TIPE3-overexpressing and knock-down NSCLC cell lines were established by transfer of TIPE3 coding sequence and shRNA, respectively. In vitro functional assays were performed to assess the effects of TIPE3 on proliferation and metastasis of NSCLC cells. Tumor xenograft mouse model was used to examine the roles of TIPE3 in growth of NSCLC cells in vivo. Western blotting, immunofluorescence, and immunohistochemistry were conducted to evaluate the association of TIPE3 and molecules related to AKT/ERK1/2-GSK3β-β-catenin/Snail pathway. PI3K, MEK, or GSK3β kinase and proteasome inhibition assays as well as β-Trcp and STUB1 siRNA assays were employed to determine the contribution of AKT/ERK1/2-GSK3β signaling and ubiquitin-proteasome pathway to the regulatory effects of TIPE3 on expression of β-catenin, Snail1, and Slug.

Results

We demonstrated that TIPE3 was elevated in lung cancer tissues and cells. The expression level of TIPE3 was positively correlated with malignant clinicopathological characteristics of lung cancer patients, such as tumor size, pathologic stage, and lymph node metastasis. Knockdown of TIPE3 suppressed the proliferation and growth of NSCLC cells as well as their migration and invasion ability, whereas TIPE3 overexpression facilitated these biological processes. Mechanistic data showed that TIPE3 promoted AKT and ERK1/2 signaling, inactivated GSK3β activity, and enhanced the expression and transcriptional activity of β-catenin, Snail1, and Slug in NSCLC cells. Kinase or proteasome inhibition and β-Trcp or STUB1 knockdown assays further revealed that TIPE3 upregulated β-catenin, Snail1, and Slug via the AKT/ERK1/2-GSK3β pathway, in an ubiquitin-proteasome-dependent manner. More importantly, clinical data demonstrated that the expression level of TIPE3 was positively associated with the activation of AKT/ERK1/2-GSK3β-β-catenin/Snail pathway in lung cancer.

Conclusions

Our findings indicate that upregulation of TIPE3 promotes the progression of human NSCLC considerably by activating β-catenin, Snail1, and Slug transcriptional signaling via the AKT/ERK1/2-GSK3β axis. Therefore, TIPE3 may represent a potential therapeutic target for NSCLC.

High Prevalence and Early Occurrence of Skeletal Complications in EGFR Mutated NSCLC Patients With Bone Metastases

Objectives

The prevalence of Skeletal Related Adverse Events (SREs) in EGFR mutated non-small cell lung cancer (NSCLC) patients with bone metastases, treated with modern tyrosine kinase inhibitors (TKIs), has been scarcely investigated.

Materials and Methods

We retrospectively evaluated the data of EGFR mutated NSCLC patients with bone metastases treated with TKIs in 12 Italian centers from 2014 to 2019, with the primary aim to explore type and frequency of SREs.

Results

Seventy-seven out of 274 patients enrolled (28%) developed at least one major SRE: 55/274 (20%) bone fractures, 30/274 (11%) spinal cord compression, 5/274 (2%) hypercalcemia. Median time to the onset of SRE was 3.63 months. Nine patients (3%) underwent bone surgery and 150 (55%) radiation therapy on bone. SREs were more frequently observed within the 12 months from TKI start than afterwards (71 vs 29%, p 0.000). Patient Performance Status and liver metastases where independently associated with the risk of developing SREs. Median TKI exposure and overall survival were 11 and 28 months, respectively. Bone resorption inhibitors were associated with a lower risk of death (HR 0.722, 95% CI: 0.504–1.033, p = 0.075) although not statistically significant at multivariate analysis.

Conclusion

Bone metastatic NSCLC patients with EGFR mutated disease, treated with EGFR TKIs, have a relatively long survival expectancy and are at high risk to develop SREs. The early SRE occurrence after the TKI start provides the rationale to administer bone resorption inhibitors.

TRIP13 promotes the proliferation and invasion of lung cancer cells via the Wnt signaling pathway and epithelial-mesenchymal transition

Thyroid hormone receptor interactor 13 (TRIP13) is an ATPase that has been found to be overexpressed in many tumors. The aim of this study was to investigate the role of TRIP13 and its mechanism of action in lung cancer. The expression of TRIP13 was examined in lung cancer tissues and corresponding normal lung tissues by western blotting. TRIP13 was overexpressed or knocked down by transient transfection or siRNA interference in lung cancer cells, respectively. The expression of key proteins associated with the Wnt signaling pathway and epithelial-mesenchymal transition (EMT) was assessed. The interaction between TRIP13 and low-density lipoprotein receptor-related protein 6 (LRP6) was examined by co-immunoprecipitation and laser confocal immunofluorescence. Moreover, this study determined the proliferative and invasive ability of cells through colony formation, cell proliferation, and Matrigel invasion assays. The expression of TRIP13 was higher in lung cancer tissues than in normal lung tissues (p = 0.002), and this correlated with poor patient prognosis (p < 0.001). In addition, overexpression of TRIP13 enhanced the levels of active β-catenin and target proteins of the Wnt signaling pathways (p < 0.05). This study found that TRIP13 can co-localize and bind with LRP6. Furthermore, overexpression of TRIP13 caused the upregulation of N-cadherin, Snail, and vimentin, and the downregulation of E-cadherin (p < 0.05). The aforementioned results were reversed after knocking down the expression of TRIP13 (p < 0.05). TRIP13 is highly expressed in lung cancers, indicating poor prognosis. overexpression of TRIP13 promotes the proliferative and invasive ability of lung cancer cells via the activation of Wnt signaling pathway and EMT.

IMPDH2 promotes cell proliferation and epithelial-mesenchymal transition of non-small cell lung cancer by activating the Wnt/β-catenin signaling pathway

Inosine 5'-monophosphate dehydrogenase type II (IMPDH2) is an important enzyme involved in the biosynthesis of guanine nucleotides. Therefore, the present study aimed to investigate the potential and molecular mechanism of IMPDH2 in non-small cell lung cancer (NSCLC). Reverse transcription-quantitative PCR and immunohistochemistry were used to detect IMPDH2 expression levels in NSCLC tissues and cells. A Cell Counting Kit-8 assay, colony formation assay, flow cytometry, wound healing, Transwell assay, western blotting and immunofluorescence analyses were utilized to identify the effects of upregulated IMPDH2 levels on NSCLC cells. The expression levels of IMPDH2 have been discovered to be upregulated in several types of human cancer; however, the biological and clinical value of IMPDH2 in NSCLC remains unclear. The results of the present study revealed that the expression levels of IMPDH2 were significantly upregulated in NSCLC tissues. Furthermore, the genetic knockdown of IMPDH2 significantly hindered the proliferation, apoptosis, invasion, migration and epithelial-mesenchymal transition of NSCLC cells, whereas the overexpression of IMPDH2 achieved the opposite results. In addition, the results of the present study demonstrated that the inhibition of IMPDH2 inhibited the Wnt/β-catenin signaling pathway by decreasing the expression levels of Wnt3a and β-catenin, while increasing the expression levels of phosphorylated glycogen synthase kinase-3β in NSCLC cells. These findings of the present study indicated that IMPDH2 may promote NSCLC progression by activating the Wnt/β-catenin signaling pathway, which suggested that IMPDH2 may be a novel therapeutic target for patients with NSCLC.

Antibody-Drug Conjugates in Thoracic Malignancies: Clinical Trials Reveal Both Promise and Challenges

Thoracic malignancies are the main cause of cancer-related deaths worldwide. The need to develop new therapies is therefore urgent. The recognition of new potential therapeutic targets in thoracic malignancies has prompted the development of a number of antibody-drug conjugates. This new class of potent anticancer agents is supposed to more specifically and directly target the tumor while limiting toxicity for healthy tissues by delivering a toxic payload to tumor cells that are recognized by the presence of specific cell surface antigens. Progress in the development of antibody-drug conjugates over the last decade has been significant, with several promising advances. Unfortunately, many failures have also been encountered, often because of unexpectedly severe toxicities that contradicted the assumed mechanism of action, and major challenges remain. Various techniques to reduce the toxicities associated with antibody-drug conjugates are being studied, and the panorama of antibody-drug conjugates in clinical stages continues to increase and evolve. Current efforts in the conjugation and linker chemistries could result in the successful construction of clinically effective compounds. The future clinical development of antibody-drug conjugates could benefit from the identification of such payloads that can provide more safe and effective derivatives. Highly potent compounds with reasonable aqueous solubility, non-immunogenic profile, and stability in storage and the bloodstream should be important aspects of research into cytotoxic payloads.

Roles of Wnt/β-Catenin Signaling Pathway Regulatory Long Non-Coding RNAs in the Pathogenesis of Non-Small Cell Lung Cancer

Lung cancer is one of the leading causes of cancer-related mortality worldwide. Non-small cell lung cancer (NSCLC) is the most common pathological type of lung cancer. Long non-coding RNAs (lncRNAs) are promising novel diagnostic and prognostic biomarkers, as well as potential therapeutic targets for lung cancer. Long non-coding RNAs (lncRNAs) have been demonstrated to modulate tumor cells proliferation, cell cycle progression, invasion, and metastasis by regulating gene expression at transcriptional, post-transcriptional, and epigenetic levels. The oncogenic aberrant Wnt/β-catenin signaling is prominent in lung cancer, playing a vital role in tumorigenesis, prognosis, and resistance to therapy. Interestingly, compelling studies have demonstrated that lncRNAs exert either oncogenic or tumor suppressor roles by regulating Wnt/β-catenin signaling. In this review, we aim to present the current accumulated knowledge regarding the roles of Wnt/β-catenin signaling-regulated lncRNAs in the pathogenesis of non-small cell lung cancer (NSCLC). Better understanding of the effects of lncRNAs on Wnt/β-catenin signaling might contribute to the improved understanding of the molecular tumor pathogenesis and to the uncovering of novel therapeutic targets in NSCLC.

Identification of aberrantly methylated differentially expressed genes and associated pathways in endometrial cancer using integrated bioinformatic analysis

Endometrial cancer (EC) is a fatal female reproductive tumor. Bioinformatic tools are increasingly developed to screen out molecular targets related to EC. In this study, http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE17025 and http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE40032 were obtained from Gene Expression Omnibus (GEO). “limma” package and Venn diagram tool were used to identify hub genes. FunRich was used for functional analysis. Retrieval of Interacting Genes Database (STRING) was used to analyze protein‐protein interaction (PPI) complex. Cancer Genome Atlas (TCGA), GEPIA, immunohistochemistry staining, and ROC curve analysis were carried out for validation. Univariate and multivariate regression analyses were performed to predict the risk score. Compound muscle action potential (CMap) was used to find potential drugs. GSEA was also done. We retrieved seven oncogenes which were upregulated and hypomethylated and 12 tumor suppressor genes (TSGs) which were downregulated and hypermethylated. The upregulated and hypomethylated genes were strikingly enriched in term “immune response” while the downregulated and hypermethylated genes were mainly focused on term “aromatic compound catabolic process.” TCGA and GEPIA were used to screen out EDNRB, CDO1, NDN, PLCD1, ROR2, ESPL1, PRAME, and PTTG1. Among them, ESPL1 and ROR2 were identified by Cox regression analysis and were used to construct prognostic risk model. The result showed that ESPL1 was a negative independent prognostic factor. Cmap identified aminoglutethimide, luteolin, sulfadimethoxine, and maprotiline had correlation with EC. GSEA results showed that “hedgehog signaling pathway” was enriched. This research inferred potential aberrantly methylated DEGs and dysregulated pathways may participate in EC development and firstly reported eight hub genes, including EDNRB, CDO1, NDN, PLCD1, ROR2, ESPL1, PRAME, and PTTG1 that could be used to predict EC prognosis. Aminoglutethimide and luteolin may be used to fight against EC.

The detection and analysis of differential regulatory communities in lung cancer

The tumorgenesis process of lung cancer involves the regulatory dysfunctions of multiple pathways. Although many signaling pathways have been identified to be associated with lung cancer, there are little quantitative models of how inactions between genes change during the process from normal to cancer. These changes belong to different dynamic co-expressions patterns. We quantitatively analyzed differential co-expression of gene pairs in four datasets. Each dataset included a large number of lung cancer and normal samples. By overlapping their results, we got 14 highly confident gene pairs with consistent co-expression change patterns. Some of they, such as ARHGAP30 and GIMAP4, had been recorded in STRING network database while some of them were novel discoveries, such as C9orf135 and MORN5, TEKT1 and TSPAN1 were positively correlated in both normal and cancer but more correlated in normal than cancer. These gene pairs revealed the underlying mechanisms of lung cancer occurrence.

Overexpression of miR-939-3p predicts poor prognosis and promotes progression in lung cancer

BACKGROUND

Lung cancer is the main cancer-related deaths worldwide. In this study, we explored the clinical prognostic significance and functional role of miR-939-3p in lung cancer.

METHODS

We analyzed the expression of miR-939-3p in lung cancer tissues and cells by qRT-PCR. The prognostic significance of miR-939-3p was investigated using the Kaplan-Meier survival and Cox regression analyses. The CCK-8 assay was used to determine the role of miR-939-3p in cell proliferation. Transwell assays were used to determine the effects of miR-939-3p on cell migration and invasion abilities.

RESULTS

The expression of miR-939-3p was upregulated in cancer tissues and cell lines compared with adjacent normal tissues and normal cells, respectively. The upregulated miR-939-3p was significantly associated with lymph node metastasis, TNM stage and poor prognosis of lung cancer patients. After the transfection of miR-939 mimic, overexpression of miR-939-3p promoted lung cancer cell proliferation, migration, and invasion.

CONCLUSION

These findings suggested that miR-939-3p acts as an oncogene and promotes cell proliferation, migration, and invasion in lung cancer. miR-939-3p may be a potential independent prognostic biomarker in lung cancer.

SHCBP1 promotes cisplatin induced apoptosis resistance, migration and invasion through activating Wnt pathway

Lung cancer is the leading cause for cancer death due to refractory nature to current treatment strategies, understanding the regulatory mechanism of therapy resistance of lung cancer is important for lung cancer therapy. Here, we aimed to study the role of SHCBP1 in lung cancer cisplatin resistance, we found SHCBP1 was upregulated in lung cancer tissues and cells, patients with high SHCBP1 had poor prognosis. SHC binding and spindle associated 1 (SHCBP1) overexpression promoted cisplatin induced apoptosis resistance, migration and invasion determined by apoptosis assay and transwell assay with or without Matrigel, while SHCBP1 knockdown inhibited cisplatin induced apoptosis resistance, migration and invasion. Wnt pathway promoted lung cancer progression, we found SHCBP1 activated Wnt pathway, characterized by promoting β-catenin nuclear translocation. Inhibition of Wnt pathway in SHCBP1 overexpression cells reversed the effect of SHCBP1 overexpression, confirming SHCBP1 promoted lung cancer progression through activating Wnt pathway. We also found SHCBP1 expression was positively corrected with Wnt pathway activity in lung cancer samples. In summary, we found SHCBP1 promoted cisplatin induced apoptosis resistance, migration and invasion through activating Wnt pathway, providing a potential target for lung cancer therapy.

Negative regulators of Wnt signaling in non-small cell lung cancer: Theoretical basis and therapeutic potency

Significant advances in the treatment of non-small cell lung cancer (NSCLC) have been made over the past decade, and they predominantly involve molecular targets such as epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements. However, despite the initial good response, drug resistance eventually develops. The Wnt signaling pathway has recently been considered important in embryonic development and tumorigenesis in many cancers, particularly NSCLC. Moreover, the aberrant Wnt pathway plays a significant role in NSCLC and is associated with cancer cell proliferation, metastasis, invasion and drug resistance, and the suppression of canonical or noncanonical Wnt signaling through various biological or pharmacological negative regulators has been proven to produce specific anticancer effects. Thus, blocking the Wnt pathway via its negative regulators may overcome the resistance of current treatment methods and lead to new treatment strategies for NSCLC. Therefore, in this review, we summarize recent studies on the role of negative regulators in Wnt signaling in NSCLC and the therapeutic potency of these molecules as agents and targets for NSCLC treatments.

HCRP1 inhibits cell proliferation and invasion and promotes chemosensitivity in esophageal squamous cell carcinoma

Hepatocellular carcinoma related protein 1 (HCRP1), which is essential for internalization and degradation of ubiquitinated membrane receptors, was reported to play crucial roles in cancer pathogenesis and progression. However, the functional roles of HCRP1 in esophageal squamous cell carcinoma (ESCC) remain unknown. In this study, we investigated the effects of HCRP1 on ESCC cells and the underlying mechanism. Our results demonstrated that HCRP1 was lowly expressed in ESCC tissues and cell lines. Overexpression of HCRP1 significantly suppressed ESCC cell proliferation and invasion as well as the epithelial-mesenchymal transition (EMT) process. Furthermore, HCRP1 increased the sensitivity of ESCC cells towards cisplatin/fluorouracil. Mechanistically, HCRP1 inhibited the activity of Wnt/β-catenin signaling pathway in ESCC cells. In conclusion, these findings indicated that HCRP1 suppressed ESCC cell proliferation and invasion through regulation of the Wnt/β-catenin pathway. Therefore, HCRP1 may function as a tumor suppressor in ESCC progression.

microRNA-383 regulates cell viability and apoptosis by mediating Wnt/β-catenin signaling pathway in non-small cell lung cancer

The aim of this study was to investigate the roles of microRNA-383 (miRNA-383) in progression of non-small cell lung cancer (NSCLC) and the potential mechanism. The expressions of miR-383 and Wnt1 protein were detected in lung cancer tissues and cells by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis. After the transfection of miR-383 mimics, si-Wnt1 or miR-383+Wnt1, the viability and apoptosis of NSCLC cells were detected by cell counting kit-8 and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling, respectively. The interaction between miR-383 and Wnt1 was investigated by luciferase activity and Western blot analysis. Cells stably transfected with miR-383 mimics were inoculated into the right axillary of nude mice by subcutaneous injection. The tumor volume and weight were measured, and the expressions of miR-383, Wnt1, β-catenin, and cyclin D1 were detected by qRT-PCR and Western blot analysis. The expression of miR-383 was significantly decreased, and the level of Wnt1 was significantly increased (P < 0.05) in lung cancer tissues and cells. Upregulation of miR-383 or inhibition of Wnt1 expression inhibited the cell viability and induce apoptosis in NSCLC cells. Moreover, Wnt1 was the target gene of miR-383, and its overexpression weakened the regulatory effect of miR-383 on cell viability and apoptosis in NSCLC cells. Besides, the addition of miR-383 decreased the tumor volume and size and inhibited the expressions of Wnt1, β-catenin, and cyclin D1 at the protein level in nude mice. Collectively, miR-383 induced apoptosis and inhibited cell viability as well as tumorigenic capacity in nude mice via regulating the Wnt/β-catenin signaling pathway.

In silico insights on tankyrase protein: A potential target for colorectal cancer

The Wnt/β-catenin pathway plays an important regulatory role in cancer signaling and cell regenerative mechanisms. Its suppression has long been considered as an important challenge of anticancer treatment and management. The poly(ADP-ribose) polymerase (PARP) family represented as a new class of therapeutic targets with diverse potential disease indications. Tankyrase (TNKS) is considered to be a potential target for the intervention of various cancers. The main objective of the work is to explore the molecular and quantum mechanics of the drug-like compounds and to identify the potential inhibitors for TNKS protein using the structure and ligand-based virtual screening from several databases and to explore the binding pocket and interactions of active residues. The screened compounds were further filtered using binding-free energy calculation and molecular dynamics simulation studies. The results have provided a strong molecular knowledge of TNKS and offered top hit potent inhibitors. The identified lead compounds LC_40781, LC_40777, LC_39767, LC_8346, NCI_682438, and NCI_721141 were observed to have potent activity against TNKS protein. The hydrogen bonding of compounds with Asp1198, His1201, Tyr1203 in TNKS1 and Gly1032, Ser1068 in TNKS2 are the key interactions plays a major role in binding energy. Therefore, the outcome of the study would help for further validation and provides valuable information to guide the future TNKS-specific inhibitor designing. Communicated by Ramaswamy H. Sarma.

Roles of miR-200 family members in lung cancer: more than tumor suppressors

miRNAs are a class of single-stranded noncoding RNAs, which have no coding potential, but modulate many molecular mechanisms including cancer pathogenesis. miRNAs participate in cell proliferation, differentiation, apoptosis, as well as carcinogenesis or cancer progression, and their involvement in lung cancer has been recently shown. They are suggested to have bidirectional functions on important cancer-related genes so as to enhance or attenuate tumor genesis. Epithelial-mesenchymal transition (EMT) is a fundamental process which contributes to integrity of organogenesis and tissue differentiation as well as tissue repair, organ fibrosis and the progression of carcinoma, and several miRNAs were suggested to form the network regulating EMT in lung cancer, among which, miR-200 family members (miR-200a, miR-200b, miR-200c, miR-429 and miR-141) play crucial roles in the suppression of EMT.

Assessment of the circulating klotho protein in lung cancer patients

The anti-aging factor, klotho has been identified as a tumor suppressor in various human cancers, including lung cancer. In vitro studies provided evidence that klotho expression influences the characteristics of lung cancer cells, however, in vivo results are lacking. The aim of our study was to evaluate whether circulating klotho protein might serve as a potential biomarker of lung cancer. Blood samples were taken from 45 newly diagnosed lung cancer patients (31 NSCLC, 14 SCLC) and 43 control subjects. Plasma klotho concentration was measured using ELISA. No difference in plasma klotho values was detected between patients and control subjects (366.3 (257.9-486.8) vs. 383.5 (304.6-489.7) pg/ml respectively (median (IQR)); p > 0.05). Plasma klotho levels in patients with distant metastasis did not differ from less advanced stage disease (354.2 (306.9-433.3 vs. 328.5 (242.5-419.7) pg/ml, p > 0.05). In contrast, analyzed with one-way ANOVA, significant difference (p = 0.04) was found between the examined histological types of lung cancer: adenocarcinoma (353 (329.4-438.5) pg/ml), squamous cell carcinoma (308 (209.6-348.1) pg/ml) and small cell lung cancer (388.8 (289.9-495.4) pg/ml). However, Tukey's post hoc test did not reveal significant difference between any pairs of histological groups. There was no difference between any histological subtype and health either. Our results suggest that circulating klotho protein cannot be considered as a biomarker for lung cancer. Further studies are warranted in order to examine the relationship between klotho expression in lung tissue and circulating levels of the protein, and to explore its mechanism of action in lung cancer.

Adaptive changes in global gene expression profile of lung carcinoma A549 cells acutely exposed to distinct types of AhR ligands

Exposure to persistent ligands of aryl hydrocarbon receptor (AhR) has been found to cause lung cancer in experimental animals, and lung adenocarcinomas are often associated with enhanced AhR expression and aberrant AhR activation. In order to better understand the action of toxic AhR ligands in lung epithelial cells, we performed global gene expression profiling and analyze TCDD-induced changes in A549 transcriptome, both sensitive and non-sensitive to CH223191 co-treatment. Comparison of our data with results from previously reported microarray and ChIP-seq experiments enabled us to identify candidate genes, which expression status reflects exposure of lung cancer cells to TCDD, and to predict processes, pathways (e.g. ER stress, Wnt/β-cat, IFNɣ, EGFR/Erbb1), putative TFs (e.g. STAT, AP1, E2F1, TCF4), which may be implicated in adaptive response of lung cells to TCDD-induced AhR activation. Importantly, TCDD-like expression fingerprint of selected genes was observed also in A549 cells exposed acutely to both toxic (benzo[a]pyrene, benzo[k]fluoranthene) and endogenous AhR ligands (2-(1H-Indol-3-ylcarbonyl)-4-thiazolecarboxylic acid methyl ester and 6-formylindolo[3,2-b]carbazole). Overall, our results suggest novel cellular candidates, which could help to improve monitoring of AhR-dependent transcriptional activity during acute exposure of lung cells to distinct types of environmental pollutants.

Down-regulation of FOXR2 inhibits non-small cell lung cancer cell proliferation and invasion through the Wnt/β-catenin signaling pathway

Forkhead box R2 (FOXR2), a new member of the FOX family, is an important player in a wide range of cellular processes such as proliferation, migration, differentiation and apoptosis. Recently, FOXR2 has been reported to be implicated in cancer development. However, the biological functions of FOXR2 in non-small cell lung cancer (NSCLC) remain unclear. In this study, we investigated the specific role of FOXR2 in NSCLC. The results showed that down-regulation of FOXR2 significantly inhibited NSCLC cell proliferation and invasion in vitro and suppressed NSCLC cell growth and metastasis in vivo. In addition, the decrease in FOXR2 expression markedly reduced the protein levels of β-catenin, cyclinD1 and c-Myc and hence inactivated the Wnt/β-catenin pathway in NSCLC cells. Taken together, we concluded that FOXR2 might be considered as a promising therapeutic target for NSCLC treatment.

Long non-coding RNAs RP5-821D11.7, APCDD1L-AS1 and RP11-277P12.9 were associated with the prognosis of lung squamous cell carcinoma

Lung squamous cell carcinoma (LUSC), a type of non-small cell lung carcinoma, has a poor therapeutic response, high relapse rate and poor prognosis. The present study was designed to reveal the key long non-coding RNAs (lncRNAs) associated with the prognosis of LUSC. The lncRNA expression profiles of LUSC and adjacent samples were downloaded from The Cancer Genome Atlas database. Based on the edgeR and DEseq packages, the differentially expressed lncRNAs (DELs) between LUSC and adjacent samples were obtained and the intersecting DELs were regarded as significant DELs. Subsequently, a prognostic risk model was established using Cox regression analysis and its classification effect was detected by survival analysis. Using survival analysis, the effect of the prognostic risk model was assessed in the validation set and other types of cancer. Finally, the co-expression genes of key lncRNAs were screened using the Multi-Experiment Matrix tool and the STRING database, and their functions were predicted via enrichment analysis using the Database for Annotation, Visualization and Integrated Discovery tool. A total of 2,041 significant DELs between LUSC and adjacent samples were screened. The prognostic risk model consisting of RP5-821D11.7, APCDD1L-AS1 and RP11-277P12.9 was established, which had a good classification effect. Cox multivariate regression analysis demonstrated that risk score may serve as an independent prognostic factor. Furthermore, certain co-expression genes of RP5-821D11.7 (including proliferating cell nuclear antigen), APCDD1L-AS1 (including semaphorin 5A, semaphorin 6D, ADAMTS like 1, ADAM metallopeptidase with thrombospondin type 1 motif 6, slit guidance ligand 3, and tenascin C) and RP11-277P12.9 (including Wnt family member 2B) were identified. Additionally, ‘positive regulation of cell migration’ and ‘proteinaceous extracellular matrix’ were enriched. In conclusion, the expression levels of the lncRNAs RP5-821D11.7, APCDD1L-AS1 and RP11-277P12.9 may affect the prognosis of LUSC.

Lung Cancer Chemopreventive Activity of Patulin Isolated from Penicillium vulpinum

Lung cancer is the most lethal form of cancer in the world. Its development often involves an overactivation of the nuclear factor kappa B (NF-κB) pathway, leading to increased cell proliferation, survival, mobility, and a decrease in apoptosis. Therefore, NF-κB inhibitors are actively sought after for both cancer chemoprevention and therapy, and fungi represent an interesting unexplored reservoir for such molecules. The aim of the present work was to find naturally occurring lung cancer chemopreventive compounds by investigating the metabolites of Penicillium vulpinum, a fungus that grows naturally on dung. Penicillium vulpinum was cultivated in Potato Dextrose Broth and extracted with ethyl acetate. Bioassay-guided fractionation of this extract was performed by measuring NF-κB activity using a HEK293 cell line transfected with an NF-κB-driven luciferase reporter gene. The mycotoxin patulin was identified as a nanomolar inhibitor of TNF-α-induced NF-κB activity. Immunocytochemistry and Western blot analyses revealed that its mechanism of action involved an inhibition of p65 nuclear translocation and was independent from the NF-κB inhibitor α (IκBα) degradation process. Enhancing its interest in lung cancer chemoprevention, patulin also exhibited antiproliferative, proapoptotic, and antimigration effects on human lung adenocarcinoma cells through inhibition of the Wnt pathway.

Cancer stem cells and differentiation therapy

Cancer stem cells can generate tumors from only a small number of cells, whereas differentiated cancer cells cannot. The prominent feature of cancer stem cells is its ability to self-renew and differentiate into multiple types of cancer cells. Cancer stem cells have several distinct tumorigenic abilities, including stem cell signal transduction, tumorigenicity, metastasis, and resistance to anticancer drugs, which are regulated by genetic or epigenetic changes. Like normal adult stem cells involved in various developmental processes and tissue homeostasis, cancer stem cells maintain their self-renewal capacity by activating multiple stem cell signaling pathways and inhibiting differentiation signaling pathways during cancer initiation and progression. Recently, many studies have focused on targeting cancer stem cells to eradicate malignancies by regulating stem cell signaling pathways, and products of some of these strategies are in preclinical and clinical trials. In this review, we describe the crucial features of cancer stem cells related to tumor relapse and drug resistance, as well as the new therapeutic strategy to target cancer stem cells named "differentiation therapy."

Sulforaphane reverses gefitinib tolerance in human lung cancer cells via modulation of sonic hedgehog signaling

Gefitinib is a targeted anticancer drug that was developed as an effective clinical therapy for lung cancer. Numerous patients develop gefitinib resistance in response to treatment. Sulforaphane (SFN) is present in cruciferous vegetables, and has been demonstrated to inhibit the malignant growth of various types of cancer cells. To investigate the role of SFN in gefitinib resistance, a gefitinib-tolerant PC9 (PC9GT) cell model was established by continually exposing PC9 cells to gefitinib. Cell viability was measured using a cell proliferation assay. Components of the sonic hedgehog (SHH) signaling pathway and markers of lung cancer stem cells were detected via western blotting. SFN markedly inhibited the proliferation of PC9GT and PC9 cells in a dose-dependent manner; combination SFN/gefitinib treatment also markedly decreased PC9GT cell proliferation, compared with SFN or gefitinib administered alone (P<0.05). Western blot analysis revealed that the expression of SHH, Smoothened (SMO), zinc finger protein GLI1 (GLI1), GLI2, CD133 and CD44 were upregulated in PC9GT cells, as compared with in PC9 cells. Furthermore, SFN markedly inhibited the expression of SHH, SMO and GLI1 in PC9GT and PC9 cells in a dose dependent manner, and SFN combined with gefitinib markedly inhibited the expression of SHH, SMO, GLI1, CD133 and CD44 in PC9GT cells when compared with SFN or gefitinib monotherapy. The results of the present study demonstrated that SFN inhibits the proliferation of gefitinib-tolerant lung cancer cells via modulation of the SHH signaling pathway. Therefore, combined SFN and gefitinib therapy may be an effective approach for the treatment of lung cancer.

FOXP3 promotes tumor growth and metastasis by activating Wnt/β-catenin signaling pathway and EMT in non-small cell lung cancer

Background

The role of cancer cell FOXP3 in tumorigenesis is conflicting. We aimed to study FOXP3 expression and regulation, function and clinical implication in human non-small cell lung cancer (NSCLC).

Methods

One hundred and six patients with histologically-confirmed NSCLC who underwent surgery were recruited for the study. Tumor samples and NSCLC cell lines were used to examine FOXP3 and its related molecules. Various cell functions related to tumorigenesis were performed. In vivo mouse tumor xenograft was used to confirm the in vitro results.

Results

NSCLC patients with the high level of FOXP3 had a significant decrease in overall survival and recurrence-free survival. FOXP3 overexpression significantly induced cell proliferation, migration, and invasion, whereas its inhibition impaired its oncogenic function. In vivo studies confirmed that FOXP3 promoted tumor growth and metastasis. The ectopic expression of FOXP3 induced epithelial–mesenchymal transition (EMT) with downregulation of E-cadherin and upregulation of N-cadherin, vimentin, snail, slug, and MMP9. The oncogenic effects by FOXP3 could be attributed to FOX3-mediated activation of Wnt/β-catenin signaling, as FOXP3 increased luciferase activity of Topflash reporter and upregulated Wnt signaling target genes including c-Myc and Cyclin D1 in NSCLC cells. Co-immunoprecipitation results further indicated that FOXP3 could physically interacted with β-catenin and TCF4 to enhance the functions of β-catenin and TCF4, inducing transcription of Wnt target genes to promote cell proliferation, invasion and EMT induction.

Conclusions

FOXP3 can act as a co-activator to facilitate the Wnt-b-catenin signaling pathway, inducing EMT and tumor growth and metastasis in NSCLC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-017-0700-1) contains supplementary material, which is available to authorized users.

In vivo gene expression profiling for chemosensitivity to docetaxel-cisplatin-5-FU (TPF) triplet regimen in laryngeal squamous cell carcinoma and the effect of TPF treatment on related gene expression in vitro

CONCLUSION

These results provided a battery of genes relating to TPF chemotherapeutic sensitivity and might act as molecular targets in laryngeal squamous cell carcinoma (LSCC) treatment. Moreover, these candidate biomarkers could contribute to LSCC individualized treatment.

OBJECTIVES

To screen out a set of candidate genes which could help to determine whether patients with LSCC could benefit from TPF induction chemotherapy.

METHOD

Gene-expression profiles in seven TPF-sensitive patients were compared to four resistant controls by microarray analysis. Subsequently, expression levels of potential biomarkers in chemosensitive cell line UMSCC5 after TPF treatment were observed by qRT-PCR.

RESULTS

Through microarray analysis, 1546 differently expressed genes were identified, of which 769 were up-regulated in TPF chemotherapy-responsive tissues, whereas 777 were down-regulated. Gene ontology (GO) analysis suggested these genes participating in physiological processes including cell differentiation, metabolism, signal transduction, and cellular component organization. Additionally, Kyoto Encyclopedia of Genes and Genomes (KEGG) database revealed that Wnt and p53 signaling pathways occupied important roles in TPF chemotherapeutic sensitivity. Moreover, in vitro cell culture experiments revealed the expression alternations of Mapk10, Jun, Vegfb, Pik3r5, Pld1, Tek, Itga6 exposed to TPF treatment by qRT-PCR, whilst providing an insight into the mechanism underlying TPF chemotherapeutic response in LSCC.

Investigational BET bromodomain protein inhibitors in early stage clinical trials for acute myelogenous leukemia (AML)

INTRODUCTION

Acute myelogenous leukemia (AML) is a heterogeneous group of malignancies driven by genetic mutations and deregulated epigenetic control. Relapse/refractory disease remains frequent in younger patients and even more so in older patients, including treatment with epigenetic drugs in this age group, mainly with hypomethylating agents. New treatment strategies are urgently needed. The recent discovery that epigenetic readers of the bromodomain (BRD) and extraterminal (BET) protein family, are crucial for AML maintenance by transcription of oncogenic c-MYC lead to rapid development of BET inhibitors entering clinical trials. Areas covered: We provide a critical overview using main sources for the use of BET inhibitors in AML treatment. Limits of this treatment approach including resistance mechanisms and future directions including development of new generation BET inhibitors and combination strategies with other drugs are detailed. Expert opinion: BET inhibitors were expected to overcome limits of conventional treatment in patients as impressive in vitro data emerged recently in well-characterized AML subsets, including those associated with poor risk characteristics in the clinic. Nevertheless single activity of BET inhibitors appears to be modest and resistance mechanisms were already identified. BET inhibitors with alternative mechanisms of action and/or combination strategies with epigenetic drugs should be tested.

Daucosterol Inhibits the Proliferation, Migration, and Invasion of Hepatocellular Carcinoma Cells via Wnt/β-Catenin Signaling

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. The purpose of this study was to determine the effects of daucosterol on HCC by investigating Wnt/β-catenin signaling. In this study, HepG2 and SMMC-7721 cells were treated with varying concentrations of daucosterol, and the corresponding inhibitory effects on HCC cells were examined via CCK-8 assays. Cell migration and invasion abilities were detected via transwell assays. β-Catenin and phospho (p)-β-catenin levels were analyzed via western blotting. Our results showed that daucosterol reduced the proliferation, migration, and invasion capacities of HCC cells in a concentration-dependent manner. In addition, daucosterol reduced the levels of β-catenin and p-β-catenin in HepG2 and SMMC-7721 cells. Furthermore, the Wnt signaling pathway inhibitor SB-216763 was used to treat HepG2 and SMMC-7721 cells with daucosterol. Our results showed that co-treatment with daucosterol and SB-216763 abolished the effects of daucosterol on cell inhibition ratios, cell migration, and cell invasion. These findings indicated that daucosterol inhibited cell migration and invasion in HCC cells via the Wnt/β-catenin signaling pathway. Therefore, our study highlights the use of daucosterol as a promising therapeutic strategy for HCC treatment.

Zinc suppresses stem cell properties of lung cancer cells through protein kinase C-mediated β-catenin degradation

Highly tumorigenic cancer stem cells (CSCs) residing in most cancers are responsible for cancer progression and treatment failure. Zinc is an element regulator of several cell functions; however, its role in regulation of stem cell program in lung cancer has not been demonstrated. The present study reveals for the first time that zinc can suppress stem cell properties of lung cancer cells. Such findings were proved in different lung cancer cell lines (H460, H23, and H292) and it was found that CSC markers (CD133 and ALDH1A1), stem cell-associated transcription factors (Oct4, Nanog, and Sox-2), and the ability to form tumor spheroid were dramatically suppressed by zinc treatments. Zinc was found to activate protein kinase C-α (PKCα) that further phosphorylated and mediated β-catenin degradation through the ubiquitin-proteasomal pathway. Zinc was found to increase the β-catenin-ubiquitin complex, which can be inhibited by a specific PKC inhibitor, bisindolylmaleimide I. Using specific reactive oxygen species detection and antioxidants, we have demonstrated that superoxide anions generated by zinc are a key upstream mechanism for PKCα activation leading to the subsequent suppression of stem cell features of lung cancer. Zinc increased cellular superoxide anions and the addition of superoxide anion scavenger prevented the activation of PKCα and β-catenin degradation. These findings indicate a novel role for zinc regulation in the PKCα/β-catenin pathway and explain an important mechanism for controlling of stem cell program in lung cancer cells.

Nigericin decreases the viability of multidrug-resistant cancer cells and lung tumorspheres and potentiates the effects of cardiac glycosides

Multiple factors including tumor heterogeneity and intrinsic or acquired resistance have been associated with drug resistance in lung cancer. Increased stemness and the plasticity of cancer cells have been identified as important mechanisms of resistance; therefore, treatments targeting cancer cells independent of stemness phenotype would be much more effective in treating lung cancer. In this article, we have characterized the anticancer effects of the antibiotic Nigericin in cells displaying varying degrees of stemness and resistance to anticancer drugs, arising from (1) routine culture conditions, (2) prolonged periods of serum starvation. These cells are highly resistant to conventional anticancer drugs such as Paclitaxel, Hydroxyurea, Colchicine, Obatoclax, Wortmannin, and LY294002, and the multidrug-resistant phenotype of cells growing under prolonged periods of serum starvation is likely the result of extensive rewiring of signaling pathways, and (3) lung tumorspheres that are enriched for cancer stem-like cells. We found that Nigericin potently inhibited the viability of cells growing under routine culture conditions, prolonged periods of serum starvation, and lung tumorspheres. In addition, we found that Nigericin downregulated the expression of key proteins in the Wnt canonical signaling pathway such as LRP6, Wnt5a/b, and β-catenin, but promotes β-catenin translocation into the nucleus. The antitumor effects of Nigericin were potentiated by the Wnt activator HLY78 and by therapeutic levels of the US Food and Drug Administration–approved drug Digitoxin and its novel synthetic analog MonoD. We believe that Nigericin may be used in a co-therapy model in combination with other novel chemotherapeutic agents in order to achieve potent inhibition of cancers that display varying degrees of stemness, potentially leading to sustained anticancer effects.

MicroRNA-targeted therapeutics for lung cancer treatment

INTRODUCTION

Lung cancer is one of the leading causes of cancer-related mortality worldwide. MicroRNAs (miRNAs) are endogenous non-coding small RNAs that repress the expression of a broad array of target genes. Many efforts have been made to therapeutically target miRNAs in cancer treatments using miRNA mimics and miRNA antagonists. Areas covered: This article summarizes the recent findings with the role of miRNAs in lung cancer, and discusses the potential and challenges of developing miRNA-targeted therapeutics in this dreadful disease. Expert opinion: The development of miRNA-targeted therapeutics has become an important anti-cancer strategy. Results from both preclinical and clinical trials of microRNA replacement therapy have shown some promise in cancer treatment. However, some obstacles, including drug delivery, specificity, off-target effect, toxicity mediation, immunological activation and dosage determination should be addressed. Several delivery strategies have been employed, including naked oligonucleotides, liposomes, aptamer-conjugates, nanoparticles and viral vectors. However, delivery remains a main challenge in miRNA-targeting therapeutics. Furthermore, immune-related serious adverse events are also a concern, which indicates the complexity of miRNA-based therapy in clinical settings.