Early Detection and Chemoprevention of Lung Cancer

Enhancement of the Tumor Suppression Effect of High-dose Radiation by Low-dose Pre-radiation Through Inhibition of DNA Damage Repair and Increased Pyroptosis

Radiation therapy has been a critical and effective treatment for cancer. However, not all cells are destroyed by radiation due to the presence of tumor cell radioresistance. In the current study, we investigated the effect of low-dose radiation (LDR) on the tumor suppressive effect of high-dose radiation (HDR) and its mechanism from the perspective of tumor cell death mode and DNA damage repair, aiming to provide a foundation for improving the efficacy of clinical tumor radiotherapy. We found that LDR pre-irradiation strengthened the HDR-inhibited A549 cell proliferation, HDR-induced apoptosis, and G2 phase cell cycle arrest under co-culture conditions. RNA-sequencing showed that differentially expressed genes after irradiation contained pyroptosis-related genes and DNA damage repair related genes. By detecting pyroptosis-related proteins, we found that LDR could enhance HDR-induced pyroptosis. Furthermore, under co-culture conditions, LDR pre-irradiation enhances the HDR-induced DNA damage and further suppresses the DNA damage-repairing process, which eventually leads to cell death. Lastly, we established a tumor-bearing mouse model and further demonstrated that LDR local pre-irradiation could enhance the cancer suppressive effect of HDR. To summarize, our study proved that LDR pre-irradiation enhances the tumor-killing function of HDR when cancer cells and immune cells were coexisting.

Potential Chemopreventive Role of Pterostilbene in Its Modulation of the Apoptosis Pathway

Cancer incidence keeps increasing every year around the world and is one of the leading causes of death worldwide. Cancer has imposed a major burden on the human population, including the deterioration of physical and mental health as well as economic or financial loss among cancer patients. Conventional cancer treatments including chemotherapy, surgery, and radiotherapy have improved the mortality rate. However, conventional treatments have many challenges; for example, drug resistance, side effects, and cancer recurrence. Chemoprevention is one of the promising interventions to reduce the burden of cancer together with cancer treatments and early detection. Pterostilbene is a natural chemopreventive compound with various pharmacological properties such as anti-oxidant, anti-proliferative, and anti-inflammatory properties. Moreover, pterostilbene, due to its potential chemopreventive effect on inducing apoptosis in eliminating the mutated cells or preventing the progression of premalignant cells to cancerous cells, should be explored as a chemopreventive agent. Hence, in the review, we discuss the role of pterostilbene as a chemopreventive agent against various types of cancer via its modulation of the apoptosis pathway at the molecular levels.

Precision Cut Lung Slices as a Preclinical Model for Non-Small Cell Lung Cancer Chemoprevention

Lung cancer chemoprevention is critical to addressing cancer burden in high-risk populations. Chemoprevention clinical trials rely on data from preclinical models; however, in vivo studies have high financial, technical, and staffing requirements. Precision cut lung slices (PCLS) provide an ex vivo model that maintains the structure and function of native tissues. This model can be used for mechanistic investigations and drug screenings and reduces the number of animals and time required to test hypotheses compared with in vivo studies. We tested the use of PCLS for chemoprevention studies, demonstrating recapitulation of in vivo models. Treatment of PCLS with the PPARγ agonizing chemoprevention agent iloprost produced similar effects on gene expression and downstream signaling as in vivo models. This occurred in both wild-type tissue and Frizzled 9 knockout tissue, a transmembrane receptor required for iloprost's preventive activity. We explored new areas of iloprost mechanisms by measuring immune and inflammation markers in PCLS tissue and media, and immune cell presence with immunofluorescence. To demonstrate the potential for drug screening, we treated PCLS with additional lung cancer chemoprevention agents and confirmed activity markers in culture. PCLS offers an intermediate step for chemoprevention research between in vitro and in vivo models that can facilitate drug screening prior to in vivo studies and support mechanistic studies with more relevant tissue environments and functions than in vitro models.

PREVENTION RELEVANCE

PCLS could be a new model for premalignancy and chemoprevention research, and this work evaluates the model with tissue from prevention-relevant genetic and carcinogen exposed in vivo mouse models, in addition to evaluating chemoprevention agents.

Aloe emodin 3-O-glucoside inhibits cell growth and migration and induces apoptosis of non-small-cell lung cancer cells via suppressing MEK/ERK and Akt signalling pathways

AIMS

Non-small-cell lung cancer (NSCLC) is the most frequent type of lung cancer with a high mortality rate. Glycosylation of phenolic compounds may increase water-solubility and pharmacological activities and reduce the toxicity of aglycones. This study aimed to evaluate and compare the anticancer effect of aloe emodin 3-O-glucoside (AE3G) and its aglycone, aloe emodin (AE), against NSCLC.

MAIN METHOD

A human adenocarcinoma cell line (A549) and BALB/c nu/nu xenograft mice harboring A549 cells were used as the NSCLC models. Inhibition of cell migration, disruption of mitochondrial membrane potential (MMP), DNA fragmentation, and expression levels of apoptotic proteins were measured by western blot, wound healing assay, JC-1 staining, or TUNEL staining. Histopathological changes in tumour tissues were observed by H&E and TUNEL staining.

RESULTS

With no significant cytotoxicity against noncancerous cells (Vero cells), AE3G (5-50 μM) significantly and more effectively inhibited the growth, attachment, migration, Bcl-2 expression, and activation of MEK/ERK and Akt signalling proteins and induced cytochrome c release and Bax expression in A549 cells than AE. AE3G augmented the collapse of MMP, cleavage of caspases (caspase 9, 8, and 3) and PARP, and DNA fragmentation. Intraperitoneal injection of AE3G (13 and 26 mg/kg/day) reduced the tumour volume and weight and induced apoptotic cell death in tumour tissues of xenograft NSCLC mice.

SIGNIFICANCE

The present study demonstrated that AE3G significantly and more effectively diminished human NSCLC cell growth and migration by triggering mitochondria-dependent intrinsic apoptosis than AE, providing AE3G as a new potent candidate to prevent or treat human NSCLC.

Antiangiogenic Phytochemicals Constituent of Diet as Promising Candidates for Chemoprevention of Cancer

Despite the extensive knowledge on cancer nature acquired over the last years, the high incidence of this disease evidences a need for new approaches that complement the clinical intervention of tumors. Interestingly, many types of cancer are closely related to dietary habits associated with the Western lifestyle, such as low fruit and vegetable intake. Recent advances around the old-conceived term of chemoprevention highlight the important role of phytochemicals as good candidates for the prevention or treatment of cancer. The potential to inhibit angiogenesis exhibited by many natural compounds constituent of plant foods makes them especially interesting for their use as chemopreventive agents. Here, we review the antitumoral potential, with a focus on the antiangiogenic effects, of phenolic and polyphenolic compounds, such as quercetin or myricetin; terpenoids, such as ursolic acid or kahweol; and anthraquinones from Aloe vera, in different in vitro and in vivo assays, and the available clinical data. Although clinical trials have failed to assess the preventive role of many of these compounds, encouraging preclinical data support the efficacy of phytochemicals constituent of diet in the prevention and treatment of cancer, but a deeper understanding of their mechanisms of action and better designed clinical trials are urgently needed.

Intranasal iloprost prevents tumors in a murine lung carcinogenesis model

Lung cancer chemoprevention with the prostacyclin analogue iloprost is the most promising approach to date for intercepting progression of premalignant lung lesions in former smokers. Previous pre-clinical studies of iloprost used oral delivery, but a study modeling delivery directly to the target organ was needed. In vivo and in vitro studies have identified gene expression changes following iloprost treatment, including increased E-cadherin and PPAR𝛄 and decreased COX2 and Vimentin. We used tumor counts and gene expression to demonstrate the effectiveness of intranasal delivery of iloprost in a murine model of premalignant adenomas. Intranasal delivery of iloprost reduced adenoma multiplicity14 weeks after urethane exposure in FVB mice compared to untreated urethane controls. Intranasal iloprost reversed urethane-induced gene expression changes in tumors and whole lung. These results correspond to previous studies of oral iloprost and in vitro treatment of human bronchial epithelial cells. This study demonstrates that intranasal delivery of iloprost in a mouse model of lung premalignant lesions is effective chemoprevention. This will be an essential tool for exploring mechanisms and outcomes of iloprost chemoprevention, along with supporting ongoing clinical trials of inhaled iloprost chemoprevention.

Five long non-coding RNAs establish a prognostic nomogram and construct a competing endogenous RNA network in the progression of non-small cell lung cancer

BACKGROUND

Accumulating evidence has revealed that long non-coding RNAs (lncRNAs) play vital roles in the progression of non-small cell lung cancer (NSCLC). But the relationship between lncRNAs and survival outcome of NSCLC remains to be explored. Therefore, we attempt to figure out their survival roles and molecular connection in NSCLC.

METHODS

By analyzing the transcriptome profiling of NSCLC from TCGA databases, we divided patients into three groups, and identified differentially expressed lncRNAs (DELs) of each group. Next, we explored the prognostic roles of common DELs by univariate and multivariate Cox analysis, Lasson, and Kaplan-Meier analysis. Additionally, we assessed and compared the prognostic accuracy of 5 lncRNAs through ROC curves and AUC values. Ultimately, we detected their potential function by enrichment analysis and molecular connection through establishing a competing endogenous RNA (ceRNA) network.

RESULTS

One hundred ninety-seven common DELs were spotted. And we successfully screened out 5 lncRNAs related to the patient's survival, including LINC01833, AC112206.2, FAM83A-AS1, BANCR, and HOTAIR. Combing with age and AJCC stage, we constructed a nomogram that prognostic prediction was superior to the traditional parameters. Furthermore, 275 qualified mRNAs related to 5 lncRNAs were spotted. Functional analysis indicates that these lncRNAs act key roles in the progression of NSCLC, such as P53 and cell cycle signaling pathway. And ceRNA network also suggests that these lncRNAs are tightly connected with tumor progression.

CONCLUSIONS

A nomogram and ceRNA network based on 5 lncRNAs indicate that there can effectively predict the overall survival of NSCLC and potentially serve as a therapeutic guide for NSCLC.

Andrographolide Against Lung Cancer-New Pharmacological Insights Based on High-Throughput Metabolomics Analysis Combined with Network Pharmacology

Andrographolide (Andro) has known to treat various illnesses such as colds, diarrhea, fever and infectious diseases. However, the effect mechanism of Andro is still unclear. Therefore, we used high-throughput metabolomics analysis to discover biomarkers, metabolic profiles and pathways to reveal the pharmacological action and effective mechanism of Andro against lung cancer. The metabolic effects of Andro on lung cancer animal was explored by ultra-performance liquid chromatography-triple-time of flight/mass spectrometry (UPLC-TOF/MS) analysis. Our results showed that Andro exhibited significant protective effects against lung cancer. Compared with control group, a total of 25 metabolites biomarkers was identified in urine of model animals, which 18 of them were regulated toward the normal direction after Andro treatment, and network pharmacology analysis showed that they were related with 570 proteins. Biological pathways analysis showed that the 11 metabolism pathways were regulated by Andro treatment in lung cancer mouse, and amino acid metabolism and arachidonic acid metabolism have great potential as target pathways for Andro against lung cancer. It revealed that high-throughput metabolomics combined with network pharmacology analysis provides deeply insight into the therapeutic mechanisms of natural product for promoting medicine development and disease treatment.

Long Noncoding RNA KCNMB2-AS1 Increases ROCK1 Expression by Sponging microRNA-374a-3p to Facilitate the Progression of Non-Small-Cell Lung Cancer

Purpose

The expression and roles of most long noncoding RNAs (lncRNAs) in non–small-cell lung cancer (NSCLC) remain poorly understood. Thus, this study investigated KCNMB2 antisense RNA 1 (KCNMB2-AS1) expression in NSCLC and determined the roles and mechanisms of KCNMB2-AS1 in regulating NSCLC progression.

Methods

KCNMB2-AS1 expression in NSCLC tissues and cells was detected using reverse transcription-quantitative polymerase chain reaction. Cell proliferation, apoptosis, migration, and invasion were evaluated using Cell Counting Kit-8, flow cytometry, Transwell migration, and Transwell invasion assays, respectively. In vivo tumor xenograft models were constructed to assess tumorigenicity. Bioinformatics predictions were performed to identify microRNAs targeting KCNMB2-AS1. Interactions between KCNMB2-AS1 and miR-374a-3p were analyzed using RNA immunoprecipitation, luciferase reporter, and rescue experiments.

Results

KCNMB2-AS1 levels were increased in NSCLC tissues and cells. KCNMB2-AS1 silencing hindered NSCLC cell proliferation, migration, and invasion and promoted apoptosis in vitro. Additionally, KCNMB2-AS1 knockdown decreased tumor growth in vivo. Mechanistically, KCNMB2-AS1 functioned as an endogenous miR-374a-3p sponge and increased ρ-associated coiled-coil–containing protein kinase 1 (ROCK1) expression. Furthermore, increased miR-374a-3p/ROCK1 output attenuated KCNMB2-AS1 silencing-induced inhibition of NSCLC progression.

Conclusion

The KCNMB2-AS1/miR-374a-3p/ROCK1 pathway drives NSCLC progression, suggesting that this pathway can be targeted to reduce NSCLC progression.

Histopathological effect of pterostilbene as chemoprevention in N-nitroso-tri-chloroethylurea (NTCU)-induced lung squamous cell carcinoma (SCC) mouse model

BACKGROUND

Lung cancer is the leading cause of cancer-related deaths, and squamous cell carcinoma (SCC) is one of the most common types of lung cancer. Chemoprevention of lung cancer has gained increasing popularity as an alternative to treatment in reducing the burden of lung cancer. Pterostilbene (PS) may be developed as a chemopreventive agent due to its pharmacological activities, such as anti-proliferative, anti-inflammatory and antioxidant properties. This study aimed to investigate the effect of PS on the development of lung SCC in the mouse model.

METHODS

A total of 24 seven-week-old female Balb/C mice were randomly categorised into four groups, including two control groups comprising the N-nitroso-trischloroethylurea (NTCU)-induced lung SCC and vehicle control (VC) groups and two treatment groups comprising the 10mg/kg PS (PS10) and 50mg/kg PS (PS50) groups. All lung organs were harvested at week 26 for histopathological analysis.

RESULTS

All PS treatment groups showed chemopreventive activity by inhibiting the progression of lung SCC formation with PS10, resulting in mild hyperplasia, and PS50 was completely reversed in the normal bronchial epithelium layer compared with the VC group. PS treatment also reduced the expression of cytokeratin 5/6 in the bronchial epithelium layer. Both PS10 and PS50 significantly reduced the epithelium thickness compared to the NTCU group (p<0.05). PS is a potential chemopreventive agent against lung SCC growth by suppressing the progression of pre-malignant lesions and reducing the thickness of the bronchial epithelium.

CONCLUSIONS

The underlying molecular mechanisms of PS in lung SCC should be further studied.

Licochalcone A reverses NNK-induced ectopic miRNA expression to elicit in vitro and in vivo chemopreventive effects

BACKGROUND

Chemoprevention is the best cost-effective way regarding cancers. MicroRNAs (miRNAs) have been reported to be differentially expressed during the development of lung cancer. However, if lung cancer prevention can be achieved through modulating miRNAs expression so far remains unknown.

PURPOSE

To discover ectopically expressed miRNAs in NNK-induced lung cancer and clarify whether Licochalcone A (lico A) can prevent NNK-induced lung cancer by modulating miRNA expression.

STUDY DESIGN AND METHODS

A/J mice were used to construct a lung cancer model by intraperitoneal injection with physiological saline NNK (100 mg/kg). Chemopreventive effects of lico A against lung cancer at 2 mg/kg and 20 mg/kg doses were evaluated in vivo. MicroRNA array and RT-qPCR were used to assess the expression levels of miRNAs. MLE-12 cells were treated with 0.1 mg/ml NNK, stimulating the ectopic expression pattern of miR-144-3p, miR-20a-5p, miR-29c-3p, let-7d-3p, and miR-328-3p. miR-144-3p mimics and inhibitors were used to manipulate miR-144-3p levels. The effects of lico A (10 μM) on cell cycle distribution, apoptosis, and the expression of CK19, RASA1, miR-144-3p, miR-20a-5p, miR-29c-3p, let-7d-3p, and miR-328-3p in NNK-treated MLE-12 cells were studied.

RESULTS

The expression levels of miR-144-3p, miR-20a-5p, and miR-29c-3p increased, while those of let-7d-3p and miR-328-3p decreased in both NNK-induced A/J mice and MLE-12 cells. Lico A could reverse the NNK-induced ectopic miRNA (miR-144-3p, miR-20a-5p, miR-29c-3p, let-7d-3p, and miR-328-3p) expression both in vivo and in vitro and elicit in vivo lung cancer chemopreventive effect against NNK. In MLE-12 cells, the overexpression of miR-144-3p elicited the same effect as NNK regarding the expression of lung cancer biomarker CK19; the silencing of miR-144-3p reversed the effect of NNK on cell cycle distribution and apoptosis. Lico A could reverse the effect of NNK on the expression of miR-144-3p, CK19, and RASA1 (predicted target of miR-144-3p).

CONCLUSION

The present study suggests that miR-144-3p, miR-20a-5p, miR-29c-3p, let-7d-3p, and miR-328-3p were involved in the in vivo pathogenesis of NNK-induced lung cancer, and lico A could reverse the effect of NNK both in vivo and in vitro to elicit lung cancer chemopreventive effects through, at least partially, these five ectopically expressed miRNAs, especially miR-144-3p.

A seven-long noncoding RNA signature predicts overall survival for patients with early stage non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the most common cancer and cause of cancer-related mortality globally. Increasing evidence suggested that the long non-coding RNAs (lncRNAs) were involved in cancer-related death. To explore the possible prognostic lncRNA biomarkers for NSCLC patients, in the present study, we conducted a comprehensive lncRNA profiling analysis based on 1902 patients from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) datasets. In the discovery phase, we employed 682 patients from the combination of four GEO datasets (GSE30219, GSE31546, GSE33745 and GSE50081) and conducted a seven-lncRNA formula to predict overall survival (OS). Next, we validated our risk-score formula in two independent datasets, TCGA (n=994) and GSE31210 (n=226). Stratified analysis revealed that the seven-lncRNA signature was significantly associated with OS in stage I patients from both discovery and validation groups (all P<0.001). Additionally, the prognostic value of the seven-lncRNA signature was also found to be favorable in patients carrying wild-type KRAS or EGFR. Bioinformatical analysis suggested that the seven-lncRNA signature affected patients’ prognosis by influencing cell cycle-related pathways. In summary, our findings revealed a seven-lncRNA signature that predicted OS of NSCLC patients, especially in those with early tumor stage and carrying wild-type KRAS or EGFR.

IRF8 induces senescence of lung cancer cells to exert its tumor suppressive function

Lung cancer is the leading cause of cancer-related deaths worldwide. However, tumor suppressor genes remain to be systemically determined for lung cancer. Here we report interferon regulatory factor 8 (IRF8), a member of the IRF family of transcription factors, as a potent lung tumor suppressor gene. Expression of IRF8 is frequently diminished in lung tumoral tissues and is associated with prognosis of non-small cell lung cancer (NSCLC) patients. Ectopic expression of IRF8 suppresses the NSCLC cells proliferation in vitro and tumorigenic potential in vivo. More importantly, forced expression of IRF8 through infection of recombinant virus inhibits lung tumorigenesis in genetically engineered mouse model (GEMM). Mechanistically, IRF8 inhibits AKT signaling and promotes accumulation of P27 protein, which results in senescence of lung cancer cells. Ectopic expression of IRF8 in tumor cells leads to regression of lung cancer tumor nodules in a xenograft tumor model. Our data, therefore, solidly shows IRF8 to be a lung cancer suppressor gene and may denote an opportunity for therapeutic intervention of NSCLC.

Transthoracic fine-needle aspiration diagnosis of solid, subsolid, and partially calcified lung nodules: A retrospective study from a single academic center

Background:

The large-scale National Lung Cancer Screening Trial demonstrated an increased detection of early-stage lung cancers using low-dose computed tomography scan in the screening population. It also demonstrated a 20% reduction of lung cancer-related deaths in these patients.

Aims:

Although both solid and subsolid lung nodules are evaluated in studies, subsolid and partially calcified lung nodules are often overlooked.

Materials and Methods:

We reviewed transthoracic fine-needle aspiration (FNA) cases from lung nodule patients in our clinics and correlated cytological diagnoses with radiologic characteristics of lesions. A computer search of the pathology archive was performed over a period of 12 months for transthoracic FNAs, including both CT- and ultrasound-guided biopsies.

Results:

A total of 111 lung nodule cases were identified. Lesions were divided into three categories: solid, subsolid, and partially calcified nodules according to radiographic findings. Of 111 cases, the average sizes of the solid (84 cases), subsolid (22 cases), and calcified (5 cases) lesions were 1.952 ± 2.225, 1.333 ± 1.827, and 1.152 ± 1.984 cm, respectively. The cytological diagnoses of three groups were compared. A diagnosis of malignancy was made in 64.28% (54 cases) in solid, 22.72% (5 cases) in subsolid, and 20% (1 case) in partially calcified nodules. Among benign lesions, eight granulomatous inflammations were identified, including one case of solid, five cases of subsolid, and two cases of calcified nodules.

Conclusions:

Our study indicates that solid nodules have the highest risk of malignancy. Furthermore, the cytological evaluation of subsolid and partially calcified nodules is crucial for the accurate diagnosis and appropriate clinical management of lung nodule patients.

A Robust 8-Gene Prognostic Signature for Early-Stage Non-small Cell Lung Cancer

Background: The current staging system is imprecise for prognostic prediction of early-stage non-small cell lung cancer (NSCLC). This study aimed to develop a robust prognostic signature for early-stage NSCLC, allowing classification of patients with a high risk of poor outcome and specific treatment decision. Method: In the present study, a comprehensive genome-wide profiling analysis was conducted using a retrospective pool of early-stage NSCLC patient data from the previous datasets of Gene Expression Omnibus (GEO) including GSE31210, GSE37745, and GSE50081 and The Cancer Genome Atlas (TCGA). Cox proportional hazards models were implemented to determine the association between gene expression levels and overall patient survival in each dataset. The common genes among all datasets were selected as candidate prognostic genes. A risk score model was developed and validated using four independent datasets and the entire cohort. The Kaplan-Meier with log-rank test was used to assess survival difference. Results: A univariate Cox proportional hazards regression analysis for each dataset showed that a total of 2280 genes in GSE31210, 762 genes in GSE37745, 871 genes in GSE50081, and 666 genes in TCGA were identified as candidate protective genes, while overall 2131 genes in GSE31210, 913 in GSE37745, 1107 in GSE50081, and 997 in TCGA were identified as candidate risky genes. There were 8 common genes associated with overall survival, including 7 mRNA and 1 lncRNA. By using the Step-wise multivariate Cox analysis, an 8-gene prognostic signature (CDCP1, HMMR, TPX2, CIRBP, HLF, KBTBD7, SEC24B-AS1, and SH2B1) for early-stage NSCLC was developed. Patients in the high-risk group had shorter overall survival than those in the low-risk group. Multivariate regression and stratified analysis suggested that the prognostic power of the 8-gene signature was independent of other clinical factors. Furthermore, the 8-gene signature achieved AUC values of 0.726, 0.701, 0.725 and 0.650 in GSE31210, GSE37745, GSE50081 and TCGA, respectively. Moreover, the combination of the 8-gene signature and the stage resulted to a better patient classification for survival prediction and treatment decision. Conclusion: This study developed a robust gene signature with great value for prognostic prediction in early-stage NSCLC, which may contribute to patient classification and personalized treatment decisions.