An up to date look at lung cancer screening

DKK4-knockdown enhances chemosensitivity of A549/DTX cells to docetaxel

Drug resistance greatly limits docetaxel efficiency in the treatment of non-small cell lung cancer (NSCLC). Dickkopf 4 (DKK4), a negative regulator of Wnt/β-catenin pathway, is believed to be involved in various human cancers; whereas the association of DKK4 with acquired docetaxel resistance in NSCLC remains unclear. In the present study, we investigated the involvement of DKK4 in the docetaxel-resistant human lung adenocarcinoma A549 (A549/DTX) cells. Our results showed that DKK4 expression was significantly increased in the A549/DTX cells compared with in the A549 cells, as well as in the culture supernatant of A549/DTX cells. DKK4 overexpression increased the resistance of A549 cells to docetaxel. DKK4-knockdown promoted inhibition of A549/DTX cell growth, and reduced the colony formation and invasion capacity of A549/DTX cells. Moreover, DKK4-knockdown promoted the pro-apoptotic effect of docetaxel characterized with caspase 3 activation and inhibition of BCL-2 expression in A549/DTX cells, which was possibly mediated by inducing the activation of c-Jun N-terminal kinase (JNK)-related signaling pathway. Thus, our results indicated that DKK4-knockdown promoted the cytotoxic and pro-apoptotic activity of A549/DTX cells, which suggests a critical role of DKK4 in docetaxel resistance of the A549 cells and provides the potential to combine docetaxel therapy with DKK4 depletion in treating NSCLC.

FoxM1 inhibition enhances chemosensitivity of docetaxel-resistant A549 cells to docetaxel via activation of JNK/mitochondrial pathway

Docetaxel is recommended as a second-line chemotherapy agent for the non-small-cell lung cancer (NSCLC); however, drug resistance greatly limits its efficiency. Forkhead box M1 (FoxM1), an oncogenic transcription factor, is believed to be involved in the chemoresistance of various human cancers; whereas the association of FoxM1 with acquired docetaxel-resistance in NSCLC remains unclear. In the present study, we investigated the involvement of FoxM1 in the docetaxel-resistant human lung adenocarcinoma A549 cells (A549/DTX). Our results showed that FoxM1 expression was significantly increased in the A549/DTX cells compared with that in the parental A549 cells. FoxM1 siRNA silencing promoted the cytotoxic and pro-apoptotic effect of docetaxel in A549/DTX cells, which was possibly mediated through inducing the activation of c-Jun N-terminal kinases/mitochondrial signaling pathway. Our results suggest a critical role of FoxM1 in docetaxel-resistance of the A549 cells and form the basis for the development of combined therapy of docetaxel and FoxM1 depletion in treating NSCLC.

SOX17 methylation inhibits its antagonism of Wnt signaling pathway in lung cancer

The purpose of this study was to explore epigenetic changes and functions of SOX17 in human lung cancer. Five lung cancer cell lines and 88 primary lung cancer samples were examined in this study. Methylation-specific polymerase chain reaction (MSP), semi-quantitative reverse-transcription PCR, immunohistochemistry, luciferase reporter assays, colony-formation assays, and western blotting were used to analyze methylation changes and functions of SOX17 in lung cancer. SOX17 methylation was found in 60.2% of primary human lung cancer samples, and promoter region methylation of SOX17 silenced its expression. SOX17 methylation was associated with female patients and lung cancer differentiation. Colony-formation assays revealed that SOX17 suppressed lung cancer cell proliferation. Re-expression of SOX17 inhibited Wnt signaling in H23 lung cancer cell line. SOX17 acts as a Wnt signaling inhibitor.

Revolution in lung cancer: new challenges for the surgical pathologist

CONTEXT

Traditionally, lung cancer has been viewed as an aggressive, relentlessly progressive disease with few treatment options and poor survival. The traditional role of the pathologist has been primarily to differentiate small cell carcinoma from non-small cell carcinoma on biopsy and cytology specimens and to stage non-small cell carcinomas that underwent resection. In recent years, our concepts of lung cancer have undergone a revolution, including (1) the advent of successful, new, molecular-targeted therapies for lung cancer, many of which are associated with specific histologic cell types and subtypes; (2) new observations on the natural history of lung cancer derived from ongoing high-resolution computed tomography screening studies and recent histologic findings; and (3) proposals to revise the classification of lung cancers, particularly adenocarcinomas, in part because of the first 2 developments.

OBJECTIVE

To summarize the important, new developments in lung cancer, emphasizing the role of the surgical pathologist in personalized care for patients with lung cancer.

DATA SOURCES

Information about the new developments in lung cancer was obtained from the peer-review medical literature and the authors' experiences.

CONCLUSIONS

For decades, we have perceived lung cancer as a relentlessly aggressive and mostly incurable disease for which the surgical pathologist had a limited role. Today, surgical pathologists have an important and expanding role in the diagnosis and treatment of lung cancer, and it is essential to keep informed of new advances.