Disclosing Potential Therapeutic Targets Associated With Osimertinib Resistance in the Non-small Cell Lung Cancer Cell Line H1975.

BACKGROUND/AIM: Osimertinib, a third-generation epidermal growth factor receptor tyrosine kinase inhibitor, is a highly effective and valuable treatment option for advanced non-small cell lung cancer (NSCLC) patients with EGFR mutations, such as T790M. However, acquired resistance ultimately limits its clinical application. In this study, we aimed to identify potential targets for overcoming osimertinib resistance. MATERIALS AND METHODS: The H1975/OSI cell line was induced in vitro through intermittent induction. Cell activity was measured using a cell counting kit-8 assay. Uni-omics and multi-omics analyses were conducted on the transcriptomic and proteomic (4D label-free) expression profiles, which involved differential expression analysis, GO functional annotation and KEGG pathway enrichment analysis, as well as correlation analysis of transcription factors and PPI network. RESULTS: H1975/OSI cells showed resistance towards osimertinib with IC50 values approximately 5.25-fold higher than H1975 cells. A total of 2519 genes were found to be differentially expressed genes (DEGs) and 1533 proteins were found to be differentially abundant proteins (DAPs). Furthermore, 147 genes that were differentially expressed at both the transcription and protein levels (TPGs) were identified as being differentially expressed in both the transcriptome and proteome. It was revealed that many pathways related to the structure and function of ribosomes, as well as metabolites, were altered. The highest connectivity genes of 147 TPGs included NOP56, DDX21, PDCD11, CCNB1, and TOP2A. The hub genes of the transcriptional regulatory network included DDX21, KPNA2, DDX5, BRCA1, LMNB1, and HIF1A. CONCLUSION: Collectively, our high-throughput analysis uncovered functional properties that interacted with gene signatures of H1975/OSI cells, and highlighted certain pathways and eleven hub genes that may be the potential targets for improving clinical osimertinib resistance.

Picropodophyllin inhibits the growth of pemetrexed-resistant malignant pleural mesothelioma via microtubule inhibition and IGF-1R-, caspase-independent pathways.

Background: Acquired pemetrexed resistance leads to treatment interruption in patients with malignant pleural mesothelioma (MPM). Insulin-like growth factor-I receptor (IGF-1R) inhibitor is a candidate for treating pemetrexed-naïve MPM. However, the efficacy of cytotoxic and targeted drugs in acquired-pemetrexed resistant MPM is unclear. We explored anticancer drugs, including the IGF-1R inhibitor picropodophyllin, against acquired pemetrexed-resistant MPMs. Methods: Acquired pemetrexed-resistant human MPM cell lines, named as H2452/PEM and 211H/PEM after their parental lines H2452 and 211H, respectively, were established by exposure to pemetrexed in vitro. Picropodophyllin and siRNA for IGF-1R knockdown were used to evaluate the efficacy of IGF-1R inhibition. Immunofluorescence was used to evaluate microtubule localization. The efficacy of picropodophyllin was evaluated in 3-dimensional MPM models. Results: The acquired pemetrexed-resistant MPM lines retained their resistance after the removal of culture treatment. IGF-1R levels in H2452/PEM cells were higher than those in H2452 cells but not in 211H/PEM cells compared to the respective parental line. Picropodophyllin induced sub-G1 arrest in H2452/PEM cells but induced G2/M phase arrest in 211H/PEM cells, leading to caspase-independent cell death in the two acquired pemetrexed-resistant MPM lines. Although picropodophyllin inhibited phosphorylation of IGF-1R, specific inhibition of IGF-1R by RNA interference did not reduce the viability of pemetrexed-resistant MPM lines. Additionally, picropodophyllin reduced the viability of both IGF-1R knockdown pemetrexed-resistant MPM cells. Picropodophyllin was cytotoxic in acquired-pemetrexed-resistant MPM lines because of inhibition of microtubule formation and induction of aberrant mitosis. Moreover, combination treatment with picropodophyllin and vinorelbine synergistically affected the pemetrexed-resistant MPM lines but not the parental lines. Furthermore, we observed a similar efficacy of picropodophyllin in 3-dimensional pemetrexed-resistant MPM models. Conclusions: Picropodophyllin may offer novel therapeutic properties for treating acquired pemetrexed-resistant MPM. Targeting tubulin may be an important strategy in the treatment of MPM after the discontinuation of pemetrexed.

The Association Between Cyclooxygenase-2 -1195G/A (rs689466) Gene Polymorphism and the Clinicopathology of Lung Cancer in the Japanese Population: A Case-Controlled Study.

The single nucleotide polymorphisms of COX-2 gene, also known as PTGS2, which encodes a pro-inflammatory factor cyclooxygenase-2, alter the risk of developing multiple tumors, but these findings are not consistent for lung cancer. We previously reported that the homozygous COX-2 -1195A genotype is associated with an increased risk for chronic obstructive pulmonary disease (COPD) in Japanese individuals. COPD is a significant risk factor for lung cancer due to genetic susceptibility to cigarette smoke. In this study, we investigated the association between COX-2 -1195G/A polymorphism and lung cancer susceptibility in the Japanese population. We evaluated the genotype distribution of COX-2 -1195G/A using a polymerase chain reaction-restriction fragment length polymorphism assay for 330 newly diagnosed patients with lung cancer and 162 healthy controls. Our results show that no relationship exists between the COX-2 -1195G/A polymorphism and the risk of developing lung cancer. However, compared to the control group, the homozygous COX-2 -1195A genotype increased the risk for lung squamous cell carcinoma (odds ratio = 2.902; 95% confidence interval, 1.171-7.195; p = 0.021), whereas no association is observed with the risk for adenocarcinoma. In addition, Kaplan-Meier analysis shows that the genotype distribution of homozygous COX-2 -1195A does not correlate with the overall survival of patients with lung squamous cell carcinoma. Thus, we conclude that the homozygous COX-2 -1195A genotype confers an increased risk for lung squamous cell carcinoma in Japanese individuals and could be used as a predictive factor for early detection of lung squamous cell carcinoma.

ESRP1 as a prognostic factor of non-small-cell lung cancer is related to the EMT transcription factor of Twist.

OBJECTIVE: Non-small-cell lung cancer (NSCLC) is one of the most common fatal cancers in the world. Although the treatment of NSCLC has been significantly improved, there is still an unmet need to identify novel targets for developing therapeutic agents and diagnostic/prognostic markers. The aim of this study is explore the role and underlying mechanism of the epithelial splicing regulatory protein (ESRP1) in the development and progression of NSCLC. METHODS: A total of 115 participants, 65 cases of NSCLC, 20 cases of precancerous lesions, and 30 cases of benign lung nodules, were included in this study. The expressions of ESRP1 and related transcription factor Twist in enrolled lung tissues were evaluated by histochemistry and immunohistochemistry assay. The survival analysis and related prognosis factors were evaluated by the Kaplan-Meier curve and Cox regression. In addition, the expression of ESRP1 and epithelial-mesenchymal transition (EMT)related transcription factor Twist and EMT markers E-cadherin and N-cadherin were ascertained by immunohistochemical and immunoblotting assay on A549 lung adenocarcinoma cell lines that were exposed to transforming growth factor ß1 (TGFß1). RESULTS: Compared with normal lung tissues, the abundance of ESRP1 protein was significantly increased in precancerous lesions and lung cancer. Correlation analysis demonstrated that ESRP1 was an independent prognostic factor in NSCLC. The expression of ESRP1 and Twist was positively correlated in lung tissues (r = 0.285, p < 0.001). In vitro analysis further showed that TGFß1 could upregulate the expression of EMT transcription factor Twist while downregulating ESRP1. CONCLUSIONS: Our data suggest that the aberrant expression of ESRP1 is an early event in the development of NSCLC. The ESRP1 could serve as a prognostic biomarker for NSCLC, particularly when combined with Twist. The Twist negatively regulated the expression of ESRP1, emphasizing the role of the TGFß/ESRP1 pathway in the development of NSCLC, which warrants further investigation.

Anticancer Activity of ZnO Nanoparticles against Human Small-Cell Lung Cancer in an Orthotopic Mouse Model.

Small-cell lung cancer, a highly malignant form of lung cancer, often responds to first-line treatments but relapses in most cases with resistance to further treatments. We tested zinc oxide (ZnO) nanoparticles against small-cell lung cancer and other cancer cell lines, in light of reported anticancer effects in vitro Because of a strong safety record, ZnO nanoparticles are frequently used in biomedical research, including in cellular imaging and drug delivery, and have been used for many years in several commercial products such as skin care agents. Strikingly, ZnO nanoparticles were genotoxic against small-cell lung cancer cells, resulting in low viability, even in cells orthotopically grafted onto mouse models. However, the nanoparticles were less cytotoxic against normal lung-derived cells and did not elicit observable adverse effects after intravenous administration. ZnO nanoparticles were also found to induce highly reactive oxygen species and DNA leakage from nuclei. This study is the first comprehensive evaluation of the anticancer effects of ZnO nanoparticles in vitro and in vivo and highlights new therapeutic opportunities against small-cell lung cancer.

Protein tyrosine kinase 2: a novel therapeutic target to overcome acquired EGFR-TKI resistance in non-small cell lung cancer.

BACKGROUND: Protein tyrosine kinase 2 (PTK2) expression has been reported in various types of human epithelial cancers including lung cancer; however, the role of PTK2 in epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) has not been elucidated. We previously reported that pemetrexed-resistant NSCLC cell line PC-9/PEM also acquired EGFR-TKI resistance with constitutive Akt activation, but we could not find a therapeutic target. METHODS: Cell viability in EGFR-mutant NSCLC cell lines was measured by the WST-8 assay. Phosphorylation antibody array assay for receptor tyrosine kinases was performed in PC-9 and PC-9/PEM cell lines. We evaluated the efficacy of EGFR and PTK2 co-inhibition in EGFR-TKI-resistant NSCLC in vitro. Oral defactinib and osimertinib were administered in mice bearing subcutaneous xenografts to evaluate the efficacy of the treatment combination in vivo. Both the PTK2 phosphorylation and the treatment combination efficacy were evaluated in erlotinib-resistant EGFR-mutant NSCLC cell lines. RESULTS: PTK2 was hyperphosphorylated in PC-9/PEM. Defactinib (PTK2 inhibitor) and PD173074 (FGFR inhibitor) inhibited PTK2 phosphorylation. Combination of PTK2 inhibitor and EGFR-TKI inhibited Akt and induced apoptosis in PC-9/PEM. The combination treatment showed improved in vivo therapeutic efficacy compared to the single-agent treatments. Furthermore, erlotinib-resistant NSCLC cell lines showed PTK2 hyperphosphorylation. PTK2 inhibition in the PTK2 hyperphosphorylated erlotinib-resistant cell lines also recovered EGFR-TKI sensitivity. CONCLUSION: PTK2 hyperphosphorylation occurs in various EGFR-TKI-resistant NSCLCs. Combination of PTK2 inhibitor and EGFR-TKI (defactinib and osimertinib) recovered EGFR-TKI sensitivity in the EGFR-TKI-resistant NSCLC. Our study result suggests that this combination therapy may be a viable option to overcome EGFR-TKI resistance in NSCLC.

Therapeutic bronchoscopy in a lung abscess secondary to broncholithiasis.

A 60-year-old woman developed a pulmonary abscess due to broncholithiasis. It was treated by bronchoscopic broncholithectomy after antibiotic administration. Broncholithiasis is a rare disease and various treatment options are available, which include bronchoscopic broncholithectomy and surgery. Bronchoscopic broncholithectomy has proved to be more useful because it can be used to easily extract the broncholith by using a balloon and haemostasis can be obtained at the same time.