Nicotine-mediated invasion and migration of non-small cell lung carcinoma cells by modulating STMN3 and GSPT1 genes in an ID1-dependent manner

Caffeic acid phenethyl ester mediates apoptosis in serum-starved HT29 colon cancer cells through modulation of heat shock proteins and MAPK pathways

Colorectal cancer (CRC) is among the most prevalent gastrointestinal cancers of epithelial origin worldwide, with over 2 million cases detected every year. Emerging evidence suggests a significant increase in the levels of inflammatory and stress-related markers in patients with CRC, indicating that oxidative stress and lipid peroxidation may influence signalling cascades involved in the progression of the disease. However, the precise molecular and cellular basis underlying CRC and their modulations during bioactive compound exposure have not yet been deciphered. This study examines the effect of caffeic acid phenethyl ester (CAPE), a natural bioactive compound, in HT29 CRC cells grown under serum-supplemented and serum-deprived conditions. We found that CAPE inhibited cell cycle progression in the G2/M phase and induced apoptosis. Migration assay confirmed that CAPE repressed cancer invasiveness. Protein localisation by immunofluorescence microscopy and protein expression by western blot analysis reveal increased expressions of key inflammatory signalling mediators such as p38α, Jun N-terminal kinase and extracellular signal-regulated kinase (ERK) proteins. Molecular docking data demonstrates that CAPE shows a higher docking score of -5.35 versus -4.59 to known p38 inhibitor SB203580 as well as a docking score of -4.17 versus -3.86 to known ERK1/2 inhibitor AZD0364. Co-immunoprecipitation data reveals that CAPE treatment effectively downregulates heat shock protein (HSP) expression in both sera-supplemented and limited conditions through its interaction with mitogen-activated protein kinase 14 (MAPK14). These results suggest that stress induction via serum starvation in HT29 CRC cells leads to the induction of apoptosis and co-ordinated activation of MAPK-HSP pathways. Molecular docking studies support that CAPE could serve as an effective inhibitor to target p38 and MAPK compared to their currently known inhibitors.

Identification and validation of a dysregulated TME-related gene signature for predicting prognosis, and immunological properties in bladder cancer

Background

During tumor growth, tumor cells interact with their tumor microenvironment (TME) resulting in the development of heterogeneous tumors that promote tumor occurrence and progression. Recently, there has been extensive attention on TME as a possible therapeutic target for cancers. However, an accurate TME-related prediction model is urgently needed to aid in the assessment of patients' prognoses and therapeutic value, and to assist in clinical decision-making. As such, this study aimed to develop and validate a new prognostic model based on TME-associated genes for BC patients.

Methods

Transcriptome data and clinical information for BC patients were extracted from The Cancer Genome Atlas (TCGA) database. Gene Expression Omnibus (GEO) and IMvigor210 databases, along with the MSigDB, were utilized to identify genes associated with TMEs (TMRGs). A consensus clustering approach was used to identify molecular clusters associated with TMEs. LASSO Cox regression analysis was conducted to establish a prognostic TMRG-related signature, with verifications being successfully conducted internally and externally. Gene ontology (GO), KEGG, and single-sample gene set enrichment analyses (ssGSEA) were performed to investigate the underlying mechanisms. The potential response to ICB therapy was estimated using the Tumor Immune Dysfunction and Exclusion (TIDE) algorithm and Immunophenoscore (IPS). Additionally, it was found that the expression level of certain genes in the model was significantly correlated with objective responses to anti-PD-1 or anti-PD-L1 treatment in the IMvigor210, GSE111636, GSE176307, or Truce01 (registration number NCT04730219) cohorts. Finally, real-time PCR validation was performed on 10 paired tissue samples, and in vitro cytological experiments were also conducted on BC cell lines.

Results

In BC patients, 133 genes differentially expressed that were associated with prognosis in TME. Consensus clustering analysis revealed three distinct clinicopathological characteristics and survival outcomes. A novel prognostic model based on nine TMRGs (including C3orf62, DPYSL2, GZMA, SERPINB3, RHCG, PTPRR, STMN3, TMPRSS4, COMP) was identified, and a TMEscore for OS prediction was constructed, with its reliable predictive performance in BC patients being validated. MultiCox analysis showed that the risk score was an independent prognostic factor. A nomogram was developed to facilitate the clinical viability of TMEscore. Based on GO and KEGG enrichment analyses, biological processes related to ECM and collagen binding were significantly enriched among high-risk individuals. In addition, the low-risk group, characterized by a higher number of infiltrating CD8+ T cells and a lower burden of tumor mutations, demonstrated a longer survival time. Our study also found that TMEscore correlated with drug susceptibility, immune cell infiltration, and the prediction of immunotherapy efficacy. Lastly, we identified SERPINB3 as significantly promoting BC cells migration and invasion through differential expression validation and in vitro phenotypic experiments.

Conclusion

Our study developed a prognostic model based on nine TMRGs that accurately and stably predicted survival, guiding individual treatment for patients with BC, and providing new therapeutic strategies for the disease.

REST Is Not Resting: REST/NRSF in Health and Disease

Chromatin modifications play a crucial role in the regulation of gene expression. The repressor element-1 (RE1) silencing transcription factor (REST), also known as neuron-restrictive silencer factor (NRSF) and X2 box repressor (XBR), was found to regulate gene transcription by binding to chromatin and recruiting chromatin-modifying enzymes. Earlier studies revealed that REST plays an important role in the development and disease of the nervous system, mainly by repressing the transcription of neuron-specific genes. Subsequently, REST was found to be critical in other tissues, such as the heart, pancreas, skin, eye, and vascular. Dysregulation of REST was also found in nervous and non-nervous system cancers. In parallel, multiple strategies to target REST have been developed. In this paper, we provide a comprehensive summary of the research progress made over the past 28 years since the discovery of REST, encompassing both physiological and pathological aspects. These insights into the effects and mechanisms of REST contribute to an in-depth understanding of the transcriptional regulatory mechanisms of genes and their roles in the development and progression of disease, with a view to discovering potential therapeutic targets and intervention strategies for various related diseases.

Candidate genes for domestication and resistance to cold climate according to whole genome sequencing data of Russian cattle and sheep breeds

It is known that different species of animals, when living in the same environmental conditions, can form similar phenotypes. The study of the convergent evolution of several species under the influence of the same environmental factor makes it possible to identify common mechanisms of genetic adaptation. Local cattle and sheep breeds have been formed over thousands of years under the influence of domestication, as well as selection aimed at adaptation to the local environment and meeting human needs. Previously, we identified a number of candidate genes in genome regions potentially selected during domestication and adaptation to the climatic conditions of Russia, in local breeds of cattle and sheep using whole genome genotyping data. However, these data are of low resolution and do not reveal most nucleotide substitutions. The aim of the work was to create, using the whole genome sequencing data, a list of genes associated with domestication, selection and adaptation in Russian cattle and sheep breeds, as well as to identify candidate genes and metabolic pathways for selection for cold adaptation. We used our original data on the search for signatures of selection in the genomes of Russian cattle (Yakut, Kholmogory, Buryat, Wagyu) and sheep (Baikal, Tuva) breeds. We used the HapFLK, DCMS, FST and PBS methods to identify DNA regions with signatures of selection. The number of candidate genes in potentially selective regions was 946 in cattle and 151 in sheep. We showed that the studied Russian cattle and sheep breeds have at least 10 genes in common, apparently involved in the processes of adaptation/selection, including adaptation to a cold climate, including the ASTN2, PM20D1, TMEM176A, and GLIS1 genes. Based on the intersection with the list of selected genes in at least two Arctic/Antarctic mammal species, 20 and 8 genes, have been identified in cattle and sheep, respectively, that are potentially involved in cold adaptation. Among them, the most promising for further research are the ASPH, NCKAP5L, SERPINF1, and SND1 genes. Gene ontology analysis indicated the existence of possible common biochemical pathways for adaptation to cold in domestic and wild mammals associated with cytoskeleton disassembly and apoptosis.

GSPT1 Functions as a Tumor Promoter in Human Liver Cancer

OBJECTIVE

This study analyzed the role of G1 to S phase transition 1 protein (GSPT1) in promoting progression of liver cancer cells.

METHODS

A bioinformatics database was used to analyze the expression levels of GSPT1 in liver cancer tissues and the prognosis of patients. Subsequently, Western blotting and quantitative PCR were used to verify the expression levels of GSPT1 between normal hepatocytes and hepatoma cells. We used a CRISPR/Cas9 system to construct knockouts of GSPT1 in HepG2 and HCCLM9 liver cancer cells. The effect of GSPT1 on liver cancer cell migration and invasion was analyzed using flow cytometry, migration, and tumor formation assays.

RESULTS

The Cancer Genome Atlas Liver Hepatocellular Carcinoma dataset indicated that GSPT1 expression was upregulated in liver cancer cell lines, and patients with liver cancer had poor prognosis. Knockout of GSPT1 in cells significantly inhibited tumor proliferation, cell migration, and growth in vivo.

CONCLUSION

In this study, we found that GSPT1 promotes the migration and invasion of liver cancer cells.

Cellular miR-6741-5p as a Prognostic Biomarker Predicting Length of Hospital Stay among COVID-19 Patients

Wide variability exists with host response to SARS-CoV-2 infection among individuals. Circulatory micro RNAs (miRNAs) are being recognized as promising biomarkers for complex traits, including viral pathogenesis. We hypothesized that circulatory miRNAs at 48 h post hospitalization may predict the length of stay (LOS) and prognosis of COVID-19 patients. Plasma miRNA levels were compared between three groups: (i) healthy volunteers (C); (ii) COVID-19 patients treated with remdesivir (an antiviral) plus dexamethasone (a glucocorticoid) (with or without baricitinib, a Janus kinase inhibitor) on the day of hospitalization (I); and COVID-19 patients at 48 h post treatment (T). Results showed that circulatory miR-6741-5p expression levels were significantly different between groups C and I (p < 0.0000001); I and T (p < 0.0000001); and C and T (p = 0.001). Our ANOVA model estimated that all patients with less than 12.42 Log2 CPM had a short LOS, or a good prognosis, whereas all patients with over 12.42 Log2 CPM had a long LOS, or a poor prognosis. In sum, we show that circulatory miR-6741-5p may serve as a prognostic biomarker effectively predicting mortality risk and LOS of hospitalized COVID-19 patients.

Long non-coding RNA LINC00511 promotes proliferation, invasion, and migration of non-small cell lung cancer cells by targeting miR-625-5p/GSPT1

Background

Lung cancer is a malignant tumor with a high rate of mortality and metastasis. Recently, extensive research has shown that long non-coding RNAs (lncRNAs) play a crucial role in the development and progression of non-small cell lung cancer (NSCLC). In this paper, we aimed to explore the impact of long intergenic non-coding RNA 00511 (LINC00511) on the development and metastasis of NSCLC.

Methods

A dataset containing 501 lung squamous cell carcinoma (LUSC) samples and 49 normal samples was downloaded from The Cancer Genome Atlas (TCGA). The differential gene expression and prognostic potential of LINC00511 in LUSC were analyzed by “limma” in R software. Samples of tumor tissues and normal tissues from 67 patients with NSCLC were obtained, along with clinical features. NSCLC cell proliferation, cell cycle, migration, and invasion were detected by LINC00511 knockdown with Cell Counting Kit-8 (CCK-8), flow cytometry, wound-healing assay, and Transwell experiment. The regulatory relationship between LINC00511 and microRNA (miR)-625-5p, or between miR-625-5p and G1 to S phase transition 1 (GSPT1), was detected by luciferase reporter gene assay. LINC00511, miR-625-5p, and GSPT1 expression in tumor and normal tissues and cells was determined by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot. A xenograft experiment in nude mice was performed. Ki67 and GSPT1 expression in the tumor tissues of the nude mice was assessed by immunohistochemistry.

Results

LINC00511 expression was clearly higher in the tumor tissues of the NSCLC patients than in normal tissues (P<0.001). High LINC00511 expression was related to larger tumor size, positive lymph node metastasis, advanced TNM stage, and a lower 5-year survival rate. Compared with those of the shNC group, the NSCLC cells of the shLINC00511 group had a prominently lower optical density (OD) 450 value at 72 h, a lower percentage of cells in S phase, a higher relative wound width, and a lower invasive cell number (P<0.01 or P<0.001). LINC00511 promoted GSPT1 expression via suppressing miR-625-5p. Compared with those of the shNC group, the nude mice of the shLINC00511 group had a much lower subcutaneous tumor volume and weight (P<0.05 or P<0.001).

Conclusions

lncRNA LINC00511 promotes proliferation, invasion, and migration of NSCLC cells by targeting miR-625-5p/GSPT. LINC00511 may be a potential diagnostic marker and therapeutic target for NSCLC.

A narrative review of the migration and invasion features of non-small cell lung cancer cells upon xenobiotic exposure: insights from in vitro studies

Lung cancer (LC) is the leading cause of cancer deaths worldwide, being non-small lung cancer (NSCLC) sub-types the most prevalent. Since most LC cases are only detected during the last stage of the disease the high mortality rate is strongly associated with metastases. For this reason, the migratory and invasive capacity of these cancer cells as well as the mechanisms involved have long been studied to uncover novel strategies to prevent metastases and improve the patients’ prognosis. This narrative review provides an overview of the main in vitro migration and invasion assays employed in NSCLC research. While several methods have been developed, experiments using conventional cell culture models prevailed, specifically the wound-healing and the transwell migration and invasion assays. Moreover, it is provided herewith a summary of the available information concerning chemical contaminants that may promote the migratory/invasive properties of NSCLC cells in vitro, shedding some light on possible LC risk factors. Most of the reported agents with pro-migration/invasion effects derive from cigarette smoking [e.g., Benzo(a)pyrene and cadmium] and air pollution. This review further presents several studies in which different dietary/plant-derived compounds demonstrated to impair migration/invasion processes in NSCLC cells in vitro. These chemicals that have been proposed as anti-migratory consisted mainly of natural bioactive substances, including polyphenols non-flavonoids, flavonoids, bibenzyls, terpenes, alkaloids, and steroids. Some of these compounds may eventually represent novel therapeutic strategies to be considered in the future to prevent metastasis formation in LC, which highlights the need for additional in vitro methodologies that more closely resemble the in vivo tumor microenvironment and cancer cell interactions. These studies along with adequate in vivo models should be further explored as proof of concept for the most promising compounds.

Identification of Potent, Selective, and Orally Bioavailable Small-Molecule GSPT1/2 Degraders from a Focused Library of Cereblon Modulators

Whereas the PROTAC approach to target protein degradation greatly benefits from rational design, the discovery of small-molecule degraders relies mostly on phenotypic screening and retrospective target identification efforts. Here, we describe the design, synthesis, and screening of a large diverse library of thalidomide analogues against a panel of patient-derived leukemia and medulloblastoma cell lines. These efforts led to the discovery of potent and novel GSPT1/2 degraders displaying selectivity over classical IMiD neosubstrates, such as IKZF1/3, and high oral bioavailability in mice. Taken together, this study offers compound 6 (SJ6986) as a valuable chemical probe for studying the role of GSPT1/2 in vitro and in vivo, and it supports the utility of a diverse library of CRBN binders in the pursuit of targeting undruggable oncoproteins.

Identification of GSPT1 as prognostic biomarker and promoter of malignant colon cancer cell phenotypes via the GSK-3β/CyclinD1 pathway

Colon cancer is the third most common malignant tumor and its mortality rate ranks fourth among all malignant tumor types. Bioinformatics analysis has shown that GSPT1 is dysregulated in colon cancer and is associated with tumor progression. However, the underlying mechanism remains unclear. To address this research gap, we examined the impact of GSPT1 on cell proliferation, apoptosis, migration, and invasion in vitro as well as tumor growth in vivo in colon cancer by using a Cell Counting Kit-8 assay, flow cytometry, transwell migration assay, transwell invasion assay, and tumor xenograft model-based analysis, respectively. GSPT1 was significantly up-regulated in colon cancer tissues and cell lines. High GSPT1 expression was correlated with a larger tumor size. Depletion of GSPT1 suppressed cell proliferation, migration, and invasion-induced colon cancer cell apoptosis in vitro and restrained tumorigenicity in vivo in HCT116 colon cancer cells. Taken together, our findings suggest that the GSPT1/GSK pathway exerts tumor-promoting actions in colon cancer oncogenesis and progression. The GSPT1/GSK pathway may thus be an effective target for controlling colon cancer.

Long-Chain Noncoding RNA ADAMTS9-AS2 Regulates Proliferation, Migration, and Apoptosis in Bladder Cancer Cells Through Regulating miR-182-5p

The long-chain noncoding RNA ADAMTS9-AS2 functions as a tumor suppressor gene in many cancers. However, the underlying mechanism remains to be fully elucidated in bladder cancer (BC). ADAMTS9-AS2 exhibited a lower expression level in BC samples and cell lines. In addition, overexpression of ADAMTS9-AS2 obviously suppressed proliferation and migration, and induced apoptosis of T24 cells, while transfection with the ADAMTS9-AS2 inhibitor had opposite results in 5637 cells. Furthermore, miR-182-5p was the target microRNA of ADAMTS9-AS2 and was negatively correlated with ADAMTS9-AS2 expression. Upregulation of miR-182-5p reversed the effects of ADAMTS9-AS2 overexpression on biological function in T24 cells. ADAMTS9-AS2 was a tumor suppressor that inhibited BC cell proliferation and induced cellular apoptosis by targeting miR-182-5p, and it could be a promising target for BC treatment.

Long Non-coding RNA MINCR Regulates miR-876-5p/GSPT1 Axis to Aggravate Glioma Progression

Emerging evidence underlined the crucial roles played by long non-coding RNAs (lncRNAs) in glioma. MINCR has been reported in multiple malignancies. Here, we studied its function and potential mechanism in glioma, which remain unclear. Gene expressions were analyzed by qRT-PCR assay. Both in vitro and in vivo assays were conducted to evaluate the cellular function of MINCR in glioma. The subcellular situation of MINCR was detected by subcellular fractionation and FISH assays. Luciferase reporter, RNA pull-down and RNA immunoprecipitation (RIP) assays were combined to investigate potential mechanisms of relevant genes. MINCR was up-regulated in glioma. MINCR depletion markedly refrained glioma cell proliferation, migration and invasion via sponging miR-876-5p. MiR-876-5p suppressed the malignant behaviors of glioma via binding to GSPT1. MINCR shared the binding sites with the 3'-untranslated region of GSPT1 and prevented the binding of miR-876-5p to GSPT1 mRNA, thus up-regulating the level of GSPT1. Moreover, miR-876 inhibition and GSPT1 up-regulation counteracted the functional effect induced by silencing MINCR on glioma progression. Our findings uncovered that MINCR might aggravated glioma cell proliferation and migration via acting as competing endogenous RNA (ceRNA), indicating prospective novel therapeutic target for glioma.

ID1 overexpression increases gefitinib sensitivity in non-small cell lung cancer by activating RIP3/MLKL-dependent necroptosis

ID1 is an oncogenic factor in cancer, but its role in relation to drug sensitivity is unclear. This study aimed to investigate the role of ID1 in drug sensitivity in non-small cell lung cancer (NSCLC). ID1 overexpression in NSCLC cells harboring either EGFR or KRAS mutation was performed and the sensitivity of NSCLC to gefitinib (ZD1839) was measured. A murine orthotopic lung carcinoma model with or without stable ID1 overexpression was developed and treated with gefitinib. Transcriptomic and bioinformatics analyses showed that ID1 overexpression promoted inflammation-related cell death but not apoptosis in gefitinib-treated NSCLC cells. ID1 induced necroptosis by triggering activation of RIP1/RIP3/MLKL pathways. Protein kinase array further suggested that ID1 overexpression maintains Akt activity in gefitinib-treated NSCLC cells, which in turn upregulated FLICE-like inhibitory protein to dissociate the caspase-8-RIP1 complex. The association of RIP1 and RIP3 further activated necroptotic cell death in gefitinib-treated NSCLC. In conclusion, ID1 overexpression in NSCLC induced cellular sensitivity to epidermal growth factor receptor tyrosine kinase inhibitors, regardless of the mutational status of NSCLC. The results may provide scientific evidence for optimizing the treatment outcomes of gefitinib for NSCLC patients.

Inhibitor of Differentiation 1 (Id1) in Cancer and Cancer Therapy

The inhibitor of DNA binding (Id) proteins are regulators of cell cycle and cell differentiation. Of all Id family proteins, Id1 is mostly linked to tumorigenesis, cellular senescence as well as cell proliferation and survival. Id1 is a stem cell-like gene more than a classical oncogene. Id1 is overexpressed in numerous types of cancers and exerts its promotion effect to these tumors through different pathways. Briefly, Id1 was found significantly correlated with EMT-related proteins, K-Ras signaling, EGFR signaling, BMP signaling, PI3K/Akt signaling, WNT and SHH signaling, c-Myc signaling, STAT3 signaling, RK1/2 MAPK/Egr1 pathway and TGF-β pathway, etc. Id1 has potent effect on facilitating tumorous angiogenesis and metastasis. Moreover, high expression of Id1 plays a facilitating role in the development of drug resistance, including chemoresistance, radiation resistance and resistance to drugs targeting angiogenesis. However, controversial results were also obtained. Overall, Id1 represent a promising target of anti-tumor therapeutics based on its potent promotion effect to cancer. Numerous drugs were found exerting their anti-tumor function through Id1-related signaling pathways, such as fucoidan, berberine, tetramethylpyrazine, crizotinib, cannabidiol and vinblastine.

Scutellaria Flavonoids Effectively Inhibit the Malignant Phenotypes of Non-small Cell Lung Cancer in an Id1-dependent Manner

Non-small cell lung cancer (NSCLC) is the leading cause of cancer death in the world. Inhibitor of differentiation 1 (Id1) is overexpressed in NSCLC and involved in promoting its progression and metastasis. Identifying natural compounds targeting Id1 may have utility in NSCLC treatment. Here, we sought to determine whether the anti-tumor activities of Scutellaria flavonoids (SFs) were related to Id1. We reported that three SFs (baicalin, baicalein and wogonin) exhibited strong antitumor activity in NSCLC cells in vitro and in vivo. Id1 played a pivotal role on blockage of migration and invasion by SFs. Abrogation of invasion and migration mediated by baicalin, baicalein and wogonin were totally abolished by ectopic overexpression of Id1. Mechanistically, baicalin, baicalein and wogonin activated Rap1-GTP binding and dephosphorylated Akt and Src by suppressing a7nAChR, consequently triggering inhibition of Id1. Then attenuation of its downstream mediators, VEGF-A, N-cadherin, vimentin, combined with augment of E-cadherin led to the blockage of proliferation, EMT and angiogenesis of NSCLC. Overall, our data shed light on heretofore-undescribed role of SFs as modulators of Id1, which may be a useful strategy in the treatment of NSCLC.

LncRNA DLX6-AS1 promotes the proliferation, invasion, and migration of non-small cell lung cancer cells by targeting the miR-27b-3p/GSPT1 axis

Background: Non-small cell lung cancer (NSCLC) has a significant impact on human health. The aim of this study was to explore the role of long non-coding RNA DLX6-AS1 in the proliferation, migration, and invasion of NSCLC cells. Methods: The expression of DLX6-AS1 in NSCLC tumor tissues and cell lines was examined by qRT-PCR. The effects of DLX6-AS1 knockdown on cell proliferation, migration, and invasion were assessed by Cell Counting Kit-8, wound healing, and transwell assays, respectively. Bioinformatics analyses, luciferase reporter assays, and RNA pull-down assays were employed to examine the mechanism by which DLX6-AS1 exerted its oncogenesis effects in NSCLC. The anti-tumor effect of silencing DLX6-AS1 in vivo was also evaluated. Results: DLX6-AS1 was over-expressed in NSCLC tumor tissues and cell lines and its level of expression was found to be associated with tumor size and advanced clinical stage in patients with NSCLC. Downregulation of DLX6-AS1 inhibited cell proliferation, cell clone formation, migration, and invasion of NSCLC cells. DLX6-AS1 was found to interact with miR-27b-3p/GSPT1. DLX6-AS1 expression was negatively correlated with miR-27b-3p expression, but positively correlated with GSPT1 expression in NSCLC samples. DLX6-AS1 knockdown also effectively suppressed tumor growth in an in vivo xenograft model. Conclusion: DLX6-AS1 regulated NSCLC progression by targeting the miR-27b-3p/GSPT1 axis, which may provide novel insights for NSCLC prognosis and therapy.

Inhibition of pancreatic cancer Panc1 cell migration by omeprazole is dependent on aryl hydrocarbon receptor activation of JNK

Several aryl hydrocarbon receptor (AhR)-active pharmaceuticals were screened as inhibitors of pancreatic cancer cell invasion and identified two compounds, omeprazole, that inhibited invasion. Inhibition of highly invasive Panc1 cell invasion by omeprazole involves an AhR-dependent non-genomic pathway, and omeprazole-mediated inhibition of Panc1 cell invasion was dependent on Jun-N-terminal kinase (JNK) and mitogen-activated kinase kinase 7 (MKK7). The failure of omeprazole to induce nuclear translocation of the AhR was not due to overexpression of cytosolic AhR partner proteins Hsp90 or XAP2, and results of DNA sequencing show that the AhR expressed in Panc1 cells was not mutated. Results of RNAseq studies indicate that omeprazole induced an AhR-dependent downregulation of several pro-invasion factors including activated leukocyte cell adhesion molecule (ALCAM), long chain fatty acid CoA-synthase (CSL4), stathmin 3 (STMN3) and neuropillin 2 (NRP2), and the specific functions of these genes are currently being investigated.

Rho-Family Small GTPases: From Highly Polarized Sensory Neurons to Cancer Cells

The small GTPases of the Rho-family (Rho-family GTPases) have various physiological functions, including cytoskeletal regulation, cell polarity establishment, cell proliferation and motility, transcription, reactive oxygen species (ROS) production, and tumorigenesis. A relatively large number of downstream targets of Rho-family GTPases have been reported for in vitro studies. However, only a small number of signal pathways have been established at the in vivo level. Cumulative evidence for the functions of Rho-family GTPases has been reported for in vivo studies using genetically engineered mouse models. It was based on different cell- and tissue-specific conditional genes targeting mice. In this review, we introduce recent advances in in vivo studies, including human patient trials on Rho-family GTPases, focusing on highly polarized sensory organs, such as the cochlea, which is the primary hearing organ, host defenses involving reactive oxygen species (ROS) production, and tumorigenesis (especially associated with RAC, novel RAC1-GSPT1 signaling, RHOA, and RHOBTB2).

The Influence of Nicotine on Lung Tumor Growth, Cancer Chemotherapy, and Chemotherapy-Induced Peripheral Neuropathy

Studies in animal models have suggested that nicotine, an agonist of nicotinic acetylcholine receptors, may have the potential to prevent and/or reverse the peripheral neuropathy induced by cancer chemotherapeutic drugs, such as paclitaxel and oxaliplatin. However, a large body of evidence suggests that nicotine may also stimulate lung tumor growth and/or interfere with the effectiveness of cancer chemotherapy. Whereas the reported proliferative effects of nicotine are highly variable, the antagonism of antitumor drug efficacy is more consistent, although this latter effect has been demonstrated primarily in cell culture studies. In contrast, in vitro and in vivo studies from our own laboratory indicate that nicotine fails to enhance the growth of nonsmall cell lung cancer cells or attenuate the effects of chemotherapy (paclitaxel). Given the inconsistencies in the literature, coupled with our own findings, the weight of evidence suggests that caution may be warranted in proposing to use nicotine to mitigate chemotherapy-induced peripheral neuropathy in cancer patients receiving chemotherapy. Conversely, clinical trials could be performed in patients who have completed therapy and are considered to be disease-free to determine whether nicotine, in the form of commercially available patches or gum, is effective in alleviating peripheral neuropathy symptoms.

Nicotine upregulates FGFR3 and RB1 expression and promotes non-small cell lung cancer cell proliferation and epithelial-to-mesenchymal transition via downregulation of miR-99b and miR-192

BACKGROUND

Tobacco smoke is by far the greatest risk factor for non-small-cell lung cancer (NSCLC). Nicotine, an active alkaloid in tobacco, is unable to initiate tumorigenesis in humans and rodents, but can promote the growth and metastasis of various tumors, including NSCLC, initiated by tobacco carcinogens. Recently, cigarette smoke is reported to downregulate 24 miRNAs more than 3-fold in the lungs of rats, and most of these downregulated miRNAs are associated with NSCLC initiation and development. Nicotine as the major tobacco component might be associated with the expression changes of some miRNAs.

METHODS

qRT-PCR was performed to determine the miRNA and mRNA expression, and western blot was conducted to measure protein expression. MTT assay was used to detect cell proliferation.

RESULTS

The effects of nicotine on the expression of 24 miRNAs in NSCLC cell lines were determined, and the results showed that nicotine treatment decreased miR-99b and miR-192 expression. Cell proliferation and epithelial-to-mesenchymal transition (EMT) detection showed that nicotine promoted NSCLC cell proliferation and EMT, and restoration of miR-99b or miR-192 expression relieved the effects of nicotine on NSCLC cell proliferation and EMT. Subsequently, fibroblast growth factor receptor 3 (FGFR3) and retinoblastoma 1 (RB1) were confirmed to be the targets of miR-99b and miR-192, respectively, and were upregulated by nicotine in NSCLC cells. In addition, FGFR3 or RB1 knockdown inhibited NSCLC cell proliferation and EMT.

CONCLUSION

This study, for the first time, elucidates nicotine-miR-99b/miR-192-FGFR3/RB1 regulatory network that nicotine promotes NSCLC cell proliferation and EMT by downregulating miR-99b and miR-192, and upregulating their targets FGFR3 and RB1. These findings offer novel insights into the understanding of underlying molecular mechanisms of NSCLC related with the nicotine effects.

Single cell transcriptome profiling of developing chick retinal cells

The vertebrate retina is a specialized photosensitive tissue comprised of six neuronal and one glial cell types, each of which develops in prescribed proportions at overlapping timepoints from a common progenitor pool. While each of these cells has a specific function contributing to proper vision in the mature animal, their differential representation in the retina as well as the presence of distinctive cellular subtypes makes identifying the transcriptomic signatures that lead to each retinal cell's fate determination and development challenging. We have analyzed transcriptomes from individual cells isolated from the chick retina throughout retinogenesis. While we focused our efforts on the retinal ganglion cells, our transcriptomes of developing chick cells also contained representation from multiple retinal cell types, including photoreceptors and interneurons at different stages of development. Most interesting was the identification of transcriptomes from individual mixed lineage progenitor cells in the chick as these cells offer a window into the cell fate decision-making process. Taken together, these data sets will enable us to uncover the most critical genes acting in the steps of cell fate determination and early differentiation of various retinal cell types.

A Novel Rac1-GSPT1 Signaling Pathway Controls Astrogliosis Following Central Nervous System Injury

Astrogliosis (i.e. glial scar), which is comprised primarily of proliferated astrocytes at the lesion site and migrated astrocytes from neighboring regions, is one of the key reactions in determining outcomes after CNS injury. In an effort to identify potential molecules/pathways that regulate astrogliosis, we sought to determine whether Rac/Rac-mediated signaling in astrocytes represents a novel candidate for therapeutic intervention following CNS injury. For these studies, we generated mice with Rac1 deletion under the control of the GFAP (glial fibrillary acidic protein) promoter (GFAP-Cre;Rac1^flox/flox). GFAP-Cre;Rac1^flox/flox (Rac1-KO) mice exhibited better recovery after spinal cord injury and exhibited reduced astrogliosis at the lesion site relative to control. Reduced astrogliosis was also observed in Rac1-KO mice following microbeam irradiation-induced injury. Moreover, knockdown (KD) or KO of Rac1 in astrocytes (LN229 cells, primary astrocytes, or primary astrocytes from Rac1-KO mice) led to delayed cell cycle progression and reduced cell migration. Rac1-KD or Rac1-KO astrocytes additionally had decreased levels of GSPT1 (G₁ to S phase transition 1) expression and reduced responses of IL-1β and GSPT1 to LPS treatment, indicating that IL-1β and GSPT1 are downstream molecules of Rac1 associated with inflammatory condition. Furthermore, GSPT1-KD astrocytes had cell cycle delay, with no effect on cell migration. The cell cycle delay induced by Rac1-KD was rescued by overexpression of GSPT1. Based on these results, we propose that Rac1-GSPT1 represents a novel signaling axis in astrocytes that accelerates proliferation in response to inflammation, which is one important factor in the development of astrogliosis/glial scar following CNS injury.

Expression and functions of the STAT3-SCLIP pathway in chronic myeloid leukemia cells

Chronic myeloid leukemia (CML) is a blood cell cancer with increased proliferation of granulocytes. Signal transducers and activators of transcription 3 (STAT3) is an important regulator of CML. To investigate the possible downstream factors of STAT3 and gain more insight into CML-related pathways, this study focused on the superior cervical ganglia protein 10-like protein (SCLIP, or SCG 10-like protein) and analyzed the functions of the STAT3-SCLIP pathway. The effects of STAT3 phosphorylation on SCLIP expression were examined by western blotting. Specific small interfering RNA (siRNA) was then used to knockdown SCLIP in the CML cell line K562 and the expression changes of STAT3 and factors further downstream, namely Bcl-2 and cyclin E1, were detected by RT-qPCR. Cell viability and apoptosis were also analyzed following the knockdown of SCLIP. Results showed a positive association between the phosphorylation of STAT3 and the expression of SCLIP. Knockdown of SCLIP inhibited the viability and induced the apoptosis of K562 cells. Knockdown of SCLIP did not affect the expression of STAT3 mRNA but downregulated the mRNA levels of Bcl-2 and cyclin E1. In conclusion, the results indicate that SCLIP is a direct downstream factor of STAT3, regulates Bcl-2 and cyclin E1 and mediates the viability and apoptosis of CML cells. Consisting of at least these four factors, the STAT3-SCLIP pathway might play critical roles in the regulation of CML. These data provided a more profound understanding of CML-related pathways.

Nicotine-Mediated Regulation of Nicotinic Acetylcholine Receptors in Non-Small Cell Lung Adenocarcinoma by E2F1 and STAT1 Transcription Factors

Cigarette smoking is the major risk factor for non-small cell lung cancer (NSCLC), which accounts for 80% of all lung cancers. Nicotine, the addictive component of tobacco smoke, can induce proliferation, migration, invasion, epithelial-mesenchymal transition (EMT), angiogenesis, and survival in NSCLC cell lines, as well as growth and metastasis of NSCLC in mice. This nicotine-mediated tumor progression is facilitated through activation of nicotinic acetylcholine receptors (nAChRs), specifically the α7 subunit; however, how the α7 nAChR gene is regulated in lung adenocarcinoma is not fully clear. Here we demonstrate that the α7 nAChR gene promoter is differentially regulated by E2F and STAT transcription factors through a competitive interplay; E2F1 induces the promoter, while STAT transcription factors repress it by binding to an overlapping site at a region -294 through -463bp upstream of the transcription start site. Treatment of cells with nicotine induced the mRNA and protein levels of α7 nAChR; this could be abrogated by treatment with inhibitors targeting Src, PI3K, MEK, α7 nAChR, CDK4/6 or a disruptor of the Rb-Raf-1 interaction. Further, nicotine–mediated induction of α7 nAChR was reduced when E2F1 was depleted and in contrast elevated when STAT1 was depleted by siRNAs. Interestingly, extracts from e-cigarettes, which have recently emerged as healthier alternatives to traditional cigarette smoking, can also induce α7 nAChR expression in a manner similar to nicotine. These results suggest an autoregulatory feed-forward loop that induces the levels of α7 nAChR upon exposure to nicotine, which enhances the strength of the signal. It can be imagined that such an induction of α7 nAChR contributes to the tumor-promoting functions of nicotine.

Epigallocatechin-3-gallate inhibits nicotine-induced migration and invasion by the suppression of angiogenesis and epithelial-mesenchymal transition in non-small cell lung cancer cells

Epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in green tea extract, has been found to have anticancer activities in various types of cancer. However, the underlying mechanisms are not completely clear. In the present study, the effects of EGCG on migration, invasion, angiogenesis and epithelial-mesenchymal transition (EMT) induced by nicotine in A549 non-small cell lung cancer (NSCLC) cells were investigated, and the underlying molecular mechanisms were preliminarily examined. The results showed that different concentrations of EGCG significantly inhibited nicotine-induced migration and invasion. Moreover, EGCG reversed the upregulation of HIF-1α, vascular endothelial growth factor (VEGF), COX-2, p-Akt, p-ERK and vimentin protein levels and the downregulation of p53 and β-catenin protein levels mediated by nicotine in A549 cells, but had no significant effect on their mRNA levels. Furthermore, EGCG markedly inhibited HIF-1α-dependent angiogenesis induced by nicotine in vitro and in vivo, and suppressed HIF-1α and VEGF protein expression induced by nicotine in A549 xenografts of nude mice. Taken together, the results indicated that EGCG inhibited nicotine-induced angiogenesis and EMT, leading to migration and invasion in A549 cells. The results of the present study suggested that EGCG can be developed into a potential agent for the prevention and treatment of smoking-associated NSCLC.