GPRC5A promotes paclitaxel resistance and glucose content in NSCLC.

Lung cancer is one of the most common and malignant cancers worldwide. Chemotherapy has been widely used in the clinical setting, and paclitaxel is the first-line therapy for lung cancer patients but paclitaxel resistance is the main problem. First, we successfully established paclitaxel-resistant lung cancer cells treated with elevated doses of paclitaxel for 3 months, as confirmed by the CCK-8 assay. Paclitaxel-resistant cancer cells increased glucose content. Second, Gtex, Oncomine, and gene expression omnibus database data mining identified GPRC5A, G protein-coupled receptor, as the most prominent differentially expressed gene in drug-resistant datasets including gemcitabine, paclitaxel, and gefitinib overlapped with the microarray data from cancer cell metabolism. Third, qPCR analysis and western blot technique showed that GPRC5A mRNA and protein levels were significantly enhanced in paclitaxel-resistant lung cancer cells. Fourth, functional analysis was conducted by siRNA-mediated transient knockdown of GPRC5A. Silencing GPRC5A significantly decreased paclitaxel resistance and glucose content. In the end, retinoic acid substantially upregulated GPRC5A proteins and promoted glucose content in two lung cancer cells. Kaplan-Meier plot also confirmed that lung cancer patients with high expression of GPRC5A had a relatively lower survival rate. Our study provided a potential drug target GPRC5A, which may benefit lung cancer patients with acquired paclitaxel resistance in the future and a theoretical basis for future preclinical trials.

Abnormal spindle-like microcephaly-associated protein enhances cell invasion through Wnt/ß-catenin-dependent regulation of epithelial-mesenchymal transition in non-small cell lung cancer cells.

BACKGROUND: Lung cancer is one of the most common cancer worldwide, invasion and metastasis are still the bottleneck in the clinical setting. More diagnostic markers and drug targets need to be clarified. Therefore, we screened abnormal spindle-like microcephaly-associated protein (ASPM) as our candidate gene, which is associated with the poor prognosis. The aim of the present study was to understand the roles of ASPM in cell invasion in non-small cell lung cancer (NSCLC). METHODS: Gene Expression Omnibus (GEO) datamining was used to identify ASPM. Transwell invasion assay, quantitative reverse transcription polymerase chain reaction (qRT-PCR), and Western blot analysis were performed to discover the molecular functions of ASPM. Overexpression and small interfering mediated knockdown techniques have been used to study the cell invasion hallmarks of cancer. RESULTS: ASPM stood out among all the candidate genes from GEO datamining. ASPM in lung cancer tissues has been associated with poor overall survival rate. The protein levels of ASPM has been validated using lung cancer patients' tissues, which upregulation of ASPM expression has been found in lung cancer patients. Silencing of ASPM decreased the cell invasion reflected by epithelial-mesenchymal transition (EMT) biomarkers: downregulation of vimentin and upregulation of E-cadherin. Matrix metalloproteinase (MMP) 2/9 protein levels were also affected upon transient knockdown of ASPM. Furthermore, the suppression of ASPM markedly inhibited the Wnt/ß-catenin signaling pathway in vitro. The ectopic expression of ASPM had the opposite effect. The inhibition of ß-catenin in ASPM-overexpressing lung cancer cells reduced the expression of EMT markers. The inhibitory effects on the Wnt/ß-catenin signaling pathway were attenuated in cancer cells when ASPM was silenced. These findings demonstrated that the silencing of ASPM strongly reduced cell invasion in lung cancer. CONCLUSIONS: ASPM promoted NSCLC invasion through EMT and by affecting the MMP family of proteins. The Wnt/ß-catenin signaling pathway played an indispensable role in the ASPM-mediated NSCLC EMT-invasion cascade.

[A randomized clinical study of Gefitinib and pemetrexed as second line therapy for advanced non-squamous non-small cell lung cancer].

BACKGROUND AND OBJECTIVE: Gefitinib and Pemetrexed are drugs used as second-line therapy for advanced non-small cell lung cancer (NSCLC), although studies comparing the two drugs are limited. The aim of this study is to explore the effects, safety, and quality of life (QoL) of Gefitinib and Pemetrexed on patients with advanced non-squamous NSCLC. METHODS: Forty-six advanced non-squamous NSCLC patients who failed to first-line therapy were randomly divided into two groups with 23 patients each, one using oral Gefitinib (Gefitinib group) and the other using intravenous injection Pemetrexed (Pemetrexed group). The effects, safety, and QoL were determined and analyzed. RESULTS: For the Pemetrexed group, objective response rate (ORR) was 13.0% (3/23), disease control rate (DCR) was 30.4% (7/23), and median progression-free survival (mPFS) was 3.1 months. In the Gefitinib group, ORR was 17.3% (4/23), DCR was 39.1% (9/23), and mPFS was 4.4 months. Compared with the Pemetrexed group, the ORR, DCR, and mPFS in the Gefitinib group exhibited no statistical significance (P>0.05). Furthermore, the most common toxicities in the Pemetrexed group were neutropenia (n=9, 39.13%) and fatigue (n=8, 34.78%), whereas those in the in Gefitinib group were skin rash (n=8, 34.78%) and diarrhea (n=4, 17.39%). Compared with baseline, the QoL improved in both groups but to different degrees. Likewise, emotional, functional well-being, and QoL aspects specifically related to lung cancer were better improved in the Gefitinib group than in the Pemetrexed group (P<0.05). CONCLUSIONS: The effects of Pemetrexed and Gefitinib as second line therapy were similar, although with different AEs. Both drugs could improve the QoL, but Gefitinib showed better overall results than Pemetrexed.