Prognostic and immunological potential of PPM1G in lung adenocarcinoma.

Lung cancer is one of the most common types of cancer worldwide, with the highest incidence and mortality rates. Protein phosphatase, Mg2+/Mn2+ dependent 1G (PPM1G) is a serine/threonine phosphatase, which is involved in the proliferation, invasion and metastasis of tumor cells. However, there are few reports on the role of PPM1G in lung adenocarcinoma (LUAD). The present study used publicly available data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus databases to evaluate the expression of PPM1G in LUAD, and to assess the relationship between PPM1G expression and the prognosis of patients with LUAD. Protein expression data of PPM1G obtained by immunohistochemical staining were collected from the Human Protein Atlas database. The correlation between PPM1G and immune cell infiltration and immune checkpoints was analyzed by single­sample gene set enrichment analysis of TCGA data. The Kaplan­Meier method was used for survival analysis, and univariate and multivariate Cox regression were used to analyze the effect of PPM1G on prognosis with data from TCGA database. The results showed that PPM1G was highly expressed in LUAD cancer tissues. The high expression of PPM1G was associated with poor clinical stage, T stage, N stage and overall survival in LUAD. The present study screened 29 genes related to PPM1G and closely related to the cell cycle in patients with LUAD. The expression of PPM1G was positively correlated with γδ­Τ cells, T helper 2 cells and natural killer CD56dim cells, and was negatively correlated with B cells, mast cells, plasmacytoid dendritic cells, T helper cells, macrophages, T cells, CD8 T cells, central memory T cells, effector memory T cells, neutrophils and T follicular helper cells. In addition, PPM1G was positively correlated with immune detection points. In conclusion, PPM1G may be involved in the control of the lung cancer cell cycle, and could be associated with prognosis and immune infiltration in patients with LUAD.

Circ_0007385 promotes the proliferation and inhibits the apoptosis of non-small cell lung cancer cells via miR-337-3p-dependent regulation of LMO3.

BACKGROUND: This study intended to analyze the expression characteristic, functions and underlying mechanism of circular RNA_0007385 (circ_0007385) in non-small cell lung cancer (NSCLC). METHODS AND RESULTS: RNA and protein expression was examined by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot assay. Cell counting kit 8 (CCK8) assay, colony formation assay, 5-Ethynyl-2'-deoxyuridine (EdU) assay and flow cytometry were applied to analyze cell proliferation ability. Flow cytometry was also conducted to assess cell apoptosis. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were performed to verify the predicted target relationships. Xenograft tumor model was utilized to analyze the function of circ_0007385 in vivo, and immunohistochemistry (IHC) assay was used to analyze protein expression in xenograft tumor tissues. Circ_0007385 expression was notably enhanced in NSCLC tissues and cell lines. Circ_0007385 facilitated the proliferation but suppressed the apoptosis of NSCLC cells. Circ_0007385 acted as a sponge for microRNA-337-3p (miR-337-3p), and circ_0007385 overexpression-mediated effects were largely overturned by the overexpression of miR-337-3p in NSCLC cells. MiR-337-3p interacted with the 3' untranslated region (3'UTR) of LIM-only protein 3 (LMO3). Circ_0007385 up-regulated LMO3 level by absorbing miR-337-3p in NSCLC cells. LMO3 overexpression largely reversed miR-337-3p overexpression-induced influences in NSCLC cells. Circ_0007385 knockdown significantly restrained the growth of xenograft tumors in vivo. CONCLUSION: Circ_0007385 promoted the proliferation ability and inhibited the apoptosis of NSCLC cells by binding to miR-337-3p to induce LMO3 expression.

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.