Expression of Molecular Markers in Primary Sites and Metastatic Lymph Nodes of Lung Cancer Patients

Molecular Features in Lymphatic Metastases Reflect the Metastasis Mechanism of Lymph Nodes With Non-Small-Cell Lung Cancers

Lymphatic metastasis influences clinical treatment and prognosis of patients with non-small-cell lung cancer (NSCLC). There is an urgency to understand the molecular features and mechanisms of lymph node metastasis. We analyzed the molecular features on pairs of the primary tumor and lymphatic metastasis tissue samples from 15 NSCLC patients using targeted next-generation sequencing. The potential metastasis-related genes were screened from our cohort based on cancer cell fraction. After filtering with gene functions, candidate metastasis-related events were validated in the MSK cohort with Fisher's exact test. The molecular signature and tumor mutational burden were similar in paired samples, and the average mutational concordance was 42.0% ± 28.9%. Its metastatic mechanism is potentially a linear progression based on the metastatic seeding theory. Furthermore, mutated ataxia telangiectasia mutated and Rad3-related (ATR) and tet methylcytosine dioxygenase 2 (TET2) genes were significantly enriched in lymphatic metastases (p ≤ 0.05). Alterations in these two genes could be considered metastasis-related driving events. Mutated ATR and TET2 might play an active role in the metastasis of lymph nodes with NSCLC. More case enrollment and long-term follow-up will further verify the clinical significance of these two genes.

miR-339-5p Increases Radiosensitivity of Lung Cancer Cells by Targeting Phosphatases of Regenerating Liver-1 (PRL-1)

BACKGROUND Radiotherapy is the most effective non-surgical modality in lung cancer treatment, and microRNAs (miRNAs) have been suggested as key regulators in radiosensitization. Herein, we explored the specific function of miR-339-5p in the radiosensitivity of lung cancer cells. MATERIAL AND METHODS Radiosensitivity was assessed by cell viability (CCK-8 assay), cell apoptosis, and cell cycle changes (flow cytometry). qRT-PCR and subsequent Western blot assays were used to determine the expression of miR-339-5p and other related proteins. RESULTS We demonstrated that ionizing radiation (IR) exposure impaired lung cancer cell viability, and found that miR-339-5p is a novel IR-inducible miRNA. Overexpression of miR-339-5p enhanced radiosensitivity of A549 and H460 cells by inhibiting cell viability, increasing apoptosis, inducing cell cycle arrest, and suppressing cell proliferation. Further exploration validated that miR-339-5p can target phosphatases of regenerating liver-1  (PRL-1) in lung cancer cells. Restoration of PRL-1 partially reverses the enhanced radiosensitivity of lung cancer cells induced by miR-339-5p. CONCLUSIONS Our data support that miR-339-5p has potential therapeutic value by sensitizing lung cancer cells to radiation via targeting of PRL-1.

Correlations Between mRNA Levels of Centrosomal Protein 55 (CEP55) and Clinical Features of Patients with Lung Cancer

Background

The aim of this study was to investigate the prognostic relevance of CEP55 in lung cancer (LC).

Material/Methods

LC microarray profile GSE30219 was obtained from the GEO database. The 2-sample t test was performed to clarify the difference in CEP55 expression between LC and normal lung tissue. The chi-square test and logistic regression analysis were preformed to investigate the relationship between CEP55 expression and the clinical features of LC patients. Log-rank test and Cox proportional hazards regression analysis were conducted to evaluate the disease-free survival (DFS) and overall survival (OS) of LC patients. Gene set enrichment analysis was conducted to investigate the related mechanisms.

Results

CEP55 was significantly increased in LC cells relative to normal lung tissues (P<0.0001). Univariate and multivariate correlation analyses demonstrated that CEP55 expression was associated with advanced T and N staging of LC (P<0.0001). Survival analyses indicated that CEP55 expression was an independent risk factor for DFS (HR: 1.515, 95% CI: 1.277–1.797, P<0.0001) and OS (HR: 1.436, 95% CI: 1.278–1.615). CEP55 might affect the proliferation of LC cells through Myc signaling, DNA repair, and G2M checkpoint.

Conclusions

Our results indicated that CEP55 was increased in LC cells and was associated with poor clinical outcomes of LC patients, and could be a prognostic biomarker for LC.