Minimizing residual occult nodal metastasis in NSCLC: recent advances, current status and controversies

ARHGAP9 knockdown promotes lung adenocarcinoma metastasis by activating Wnt/β-catenin signaling pathway via suppressing DKK2

This study aims to elucidate the effect of ARHGAP9 on lung adenocarcinoma (LUAD) metastasis, and preliminarily explore its molecular mechanism. As a result, we found that ARHGAP9 was downregulated and correlated with poor prognosis of LUAD. ARHGAP9 knockdown promoted LUAD cell proliferation, migration and invasion, inhibited cell apoptosis and reduced G0G1 cell cycle arrest, in contrast to the results of ARHGAP9 overexpression. Further RNA sequencing analysis demonstrated that ARHGAP9 knockdown in H1299 cells significantly reduced DKK2 (dickkopf related protein 2) expression. Silencing ARHGAP9 in H1299 cells while overexpressing DKK2, DKK2 reversed the promoted effects of ARHGAP9 knockdown on LUAD cell proliferation, migration and invasion. Meanwhile, the activity of Wnt/β-catenin signaling pathway was also reduced. Taken together, these data indicated that ARHGAP9 knockdown promoted LUAD metastasis by activating Wnt/β-catenin signaling pathway via suppressing DKK2. This may provide a new strategy for LUAD treatment.

Six Genes Associated with Lymphatic Metastasis in Colon Adenocarcinoma Linked to Prognostic Value and Tumor Immune Cell Infiltration

Objective. The aim of the study is to explore the relationship between lymphatic metastasis genes, prognosis, and immune cell infiltration in patients with colon cancer. Methods. Based on the Cancer Genome Atlas Program (TCGA) database, differentially expressed genes and prognostic genes related to colon adenocarcinoma (COAD) lymphatic metastasis were screened and intersected. We used lasso and univariate Cox regression analysis to screen core genes and establish a preliminary prediction model. GO and KEGG enrichment analysis was used for lymphatic metastasis-related genes, and single GSEA was used for the final screening results. Finally, we evaluated the relationship between identified genes and immune cell infiltration. Results. A total of 1727 genes were differentially expressed between COAD patients with TNM stages of N0 and N1. After further screening, six core genes (RNU4-2, ZNF556, RNVU1-15, NSA2P6, RN7SL767P, and RN7SL473P) were obtained, and a preliminary prediction model was established, in which ZNF556 was a risk factor, and the rest were protective factors. Single GSEA showed that pathways such as systemic lupus erythematosus might play an important role in the initial lymphatic metastasis of COAD. GO and KEGG enrichment analysis of 1727 genes supported this result. Immune infiltration analysis showed that six genes were significantly correlated with T cell and NK cell families. Conclusion. Six core genes may affect COAD initial lymphatic metastasis through the systemic lupus erythematosus pathway and immune cell infiltration.

Correlation between the Expression of VEGF and Ki67 and Lymph Node Metastasis in Non-small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

Background

Lymph node metastasis is the most common and important way of metastasis in NSCLC and is also the most important factor affecting lung cancer stage and prognosis. It is very important to analyze the relationship between the expression of vascular endothelial growth factor (VEGF) and Ki67 and lymph node metastasis (LNM) in non-small-cell lung cancer (NSCLC).

Methods

We searched the PubMed, EMBASE, and Cochrane Library and conducted meta-analyses using the R meta-package. Relative risk (RR) with a 95% confidence interval (95% CI) was the main indicator.

Results

Totally, 18 studies were considered eligible, with 4521 patients, including 1518 LNM-positive patients and 3033 LNM-negative patients. The incidence of LNM in Ki67-negative patients was lower than that in Ki67-positive patients (RR = 0.66, 95% CI: 0.44, 0.98). The incidence of LNM in VEGF-A-negative patients was lower than that in VEGF-A-positive patients (RR = 0.64, 95% CI: 0.49, 0.83). The incidence of LNM in VEGF-C negative patients was lower than that in VEGF-C positive patients (RR = 0.68, 95% CI: 0.53, 0.88). The incidence of LNM in VEGF-D negative and positive patients were of no significant differences (RR = 0.84, 95% CI: 0.61, 1.14).

Conclusion

The high expression of Ki67, VEGF-A, and VEGF-C significantly increases the risk of lymph node metastasis in NSCLC, while the VEGF-D expression has no correlation with lymph node metastasis. The expression levels of Ki67, VEGF-A, and VEGF-C show a good potential for lymph node metastasis prediction.

Partial EMT in Squamous Cell Carcinoma: A Snapshot

In the process of cancer EMT, some subgroups of cancer cells simultaneously exhibit both mesenchymal and epithelial characteristics, a phenomenon termed partial EMT (pEMT). pEMT is a plastic state in which cells coexpress epithelial and mesenchymal markers. In squamous cell carcinoma (SCC), pEMT is regulated, and the phenotype is maintained via the HIPPO pathway, NOTCH pathway and TGF-β pathways and by microRNAs, lncRNAs and the cancer microenvironment (CME); thus, SCC exhibits aggressive tumorigenic properties and high stemness, which leads collective migration and therapy resistance. Few studies have reported therapeutic interventions to address cells that have undergone pEMT, and this approach may be an effective way to inhibit the plasticity, drug resistance and metastatic potential of SCC.

Preserving NLST mortality benefits and acceptable morbidity for lung cancer surgery in a community hospital

BACKGROUND AND OBJECTIVES

The aim of this study was to demonstrate whether academic thoracic surgeons could achieve morbidity and mortality rates in community hospitals equivalent to those seen in National Lung Screening Trial (NLST).

METHODS

This was a retrospective review of community hospital lung cancer procedures for clinical Stage I-III non-small-cell lung cancers from 2007 through 2014. Variables include age, comorbidities, computed tomography (CT) characterization, and operative techniques.

RESULTS

There were 177 patients who had lung cancers removed by a minimally invasive approach (79%), including lobectomy in 127 (72%), segmentectomy in 4 (2%), and wedge-resections in 46 (26%). The median patient age was 71 years (interquartile range [IQR], 63-76). The cohort was primarily female (58%), clinical Stage I (82%), with a median tumor size of 2.3 cm (IQR, 1.5-3.3). The median length of stay was 6 days (range: 1-35). Complications were experienced by 78 (44.1%) patients, most commonly atrial fibrillation in 20 (11.3%) followed by air-leak in 19 (10.7%). There were no in-hospital deaths. Tumor location and extent of resection were associated with complications, while larger tumor size, margin contour, and resection method were associated with air-leak (all p < 0.05). Higher clinical stage and larger tumor size were associated with occult Stage III disease (both p < 0.05).

CONCLUSIONS

The low morbidity and mortality rates from the NLST were achievable in a community setting for early-stage lung cancer. Characterization of cancers using CT imaging identified factors most commonly associated with postoperative complications and the presence of occult Stage III disease.