Formylated honokiol analogs showed antitumor activity against lung carcinoma.

Honokiol, a biphenolic neolignan with inappreciable toxicity isolated from Magnolia officinalis, has been reported to have antiangiogenic and antitumor properties in several tumor cell lines and tumor xenograft models. In our previous study, structural modification by chemical synthesis has been carried out to develop novel honokiol derivatives to improve antitumor activity and clarify the structure-activity relationship. Honokiol analogs, especially 3,5'-diformylated honokiol HK-(CHO)2, have been found to moderately block the newly grown segmental vessels from the dorsal aorta in the transgenic zebrafish-based assay, show antiangiogenic property, and exert medium cytotoxicity against two lung cell lines (Lewis lung carcinoma LL/2 cells and human non-small-cell lung cancer A549 cells). However, the in-vitro and in-vivo antitumor effects of formylated honokiol derivatives against lung carcinoma remained poorly understood. In the study, two formylated honokiol derivatives also showed potent antitumor effects in the Lewis lung carcinoma cells, K-ras-dirived lung adenocarcinoma mice, and a mouse lung tumor xenograft model, with HK-(CHO)2 being most efficacious. The potential mechanism was inhibiting cell proliferation and inducing apoptosis in lung cancer by the regulation of vascular endothelial growth factor A expression. These results further suggested that HK-(CHO)2 might be potential candidates for the treatment of lung carcinoma.

Dual network analysis of transcriptome data for discovery of new therapeutic targets in non-small cell lung cancer.

The drug therapy for non-small cell lung cancer (NSCLC) have always been issues of poisonous side effect, acquired drug resistance and narrow applicable population. In this study, we built a novel network analysis method (difference- correlation- enrichment- causality- node), which was based on the difference analysis, Spearman correlation network analysis, biological function analysis and Bayesian causality network analysis to discover new therapeutic target of NSCLC in the sequencing data of BEAS-2B and 7 NSCLC cell lines. Our results showed that, as a proteasome subunit coding gene in the central of cell cycle network, PSMD2 was associated with prognosis and was an independent prognostic factor for NSCLC patients. Knockout of PSMD2 inhibited the proliferation of NSCLC cells by inducing cell cycle arrest, and exhibited marked increase of cell cycle blocking protein p21, p27 and decrease of cell cycle driven protein CDK4, CDK6, CCND1 and CCNE1. IPA and molecular docking suggested bortezomib has stronger affinity to PSMD2 compared with reported targets PSMB1 and PSMB5. In vitro and In vivo experiments demonstrated the inhibitory effect of bortezomib in NSCLC with different driven mutations or with tyrosine kinase inhibitors resistance. Taken together, bortezomib could target PSMD2, PSMB1 and PSMB5 to inhibit the proteasome degradation of cell cycle check points, to block cell proliferation of NSCLC, which was potential optional drug for NSCLC patients.

Tumor-endogenous PD-1 promotes cell proliferation and predicts poor survival in non-small cell lung cancer.

Background: Immunotherapy has emerged as a promising treatment strategy in malignant tumors. Inhibitors and neutralizing antibodies targeted PD-1 or PD-L1 show improved clinical outcomes in advanced non-small cell lung cancers (NSCLCs). Previous studies concluded that PD-1 was mainly expressed on activated T cells, B cells and other immune cells. Recently, two studies suggested that PD-1 could be detected in the tumor cells of melanoma and hepatocellular carcinoma. Tumor-endogenous PD-1 in NSCLCs has not been reported at present. Thus, we intended to explore the expression and prognostic relevance of tumor-endogenous PD-1 in NSCLCs. Methods: We detected the PD-1 expression in fresh tumor samples and tumor slices by flow cytometer and immunohistochemical analysis respectively. Overall survival (OS) and dis-ease-free survival (DFS) were analyzed with Kaplan-Meier survival curve. We explored the PD-1 expression in lung cancer cell lines and investigated its effect on cell proliferation. Results: Flow cytometry showed that tumor cells with endogenous PD-1 constituted 2.08%, 2.42%, 1.79%, and 1.21% in 4 clinical NSCLC samples respectively. Thirty-four patients (34%) in the cohort were positive for tumor-endogenous PD-1 in IHC analysis. Patients with tumor-endogenous PD-1 had significantly worse 5-year overall survival (OS) and disease-free survival (DFS). Multivariate analysis identified tumor-endogenous PD-1 as an independent risk factor (HR =3.807, 95% CI: 2.031-7.135, P<0.05). PD-1 could be observed in 4 kinds of lung cancer cell lines (A549, H1975, H1299 and HCC827). PD-1 overexpression could enhance proliferation and clone formation of these cell lines. Conclusions: PD-1 was endogenously expressed on the tumor cells of NSCLCs, and it could serve as an independent prognostic risk factor. The molecular mechanism of inferior survival of tumor-endogenous PD-1 may attribute to its role in promoting cell proliferation and clone formation. Our results demonstrated the non-immune role of PD-1 in tumor microenvironment and may provide new thinking for the therapy of NSCLCs.

Identification of GPX4 as a therapeutic target for lung adenocarcinoma after EGFR-TKI resistance.

Background: Tyrosine kinase inhibitor (TKI) treatment has significantly improved the prognosis of oncogenic-driven lung adenocarcinoma (LUAD). However, drug resistance limits the long-term benefits of patients. Therefore, there is a pressing need to explore the mechanism of TKI resistance and identify new therapeutic targets. It is possible to overcome TKI resistance by inducing tumor cell death through a new process called ferroptosis. Aberrations in ferroptosis, which is a kind of regulated cell death (RCD), has been confirmed to be involved in the development and progression of multiple tumors, and is closely related to patient survival. At present, the role of ferroptosis in TKI resistance remains unclear. Methods: Ferroptosis-related factors were isolated by expression characteristics analysis based on the multi-omics data of LUADs and normal lung tissues from The Cancer Genome Atlas (TCGA) database. Next, expression of selected ferroptosis-related factors and prognosis were analyzed. Subsequently, the differences in the expression of selected ferroptosis-related factors before and after TKI resistance on a variety of LUAD cell lines were analyzed to identify the factors that were involved in TKI resistance. Finally, the therapeutic effects were confirmed in vitro by targeting the selected ferroptosis-related factors with small molecule compounds. Results: Glutathione Peroxidase 4 (GPX4), a ferroptosis-related factor, was up-regulated in tumor tissue of LUADs, and correlated with the prognosis of patients. By detecting the expression change of GPX4 before and after TKI resistance in a variety of LUAD cell lines, we confirmed that the inhibition of GPX4 could overcome epidermal growth factor receptor (EGFR)-TKI resistance by inducing ferroptosis. Conclusions: GPX4 could serve as a novel therapeutic target for EGFR-TKI resistance in LUAD.

Identifies Immune Feature Genes for Prediction of Chemotherapy Benefit in Cancer.

Chemotherapy is still the most fundamental treatment for advanced cancers so far. Previous studies have indicated that immune cell infiltration (ICI) index could serve as a biomarker to predict chemotherapy benefit in breast cancer and colorectal cancer. However, due to different responses of tumor infiltrating immune cells (TIICs) to chemotherapy, the prediction efficiency of ICI index is not fully confirmed by now. In our study, we first extended this conclusion in 7 cancers that high ICI index could certainly indicate chemotherapy benefit (P<0.05). But we also found the fraction of different TIICs and the interaction of TIICs were varies greatly from cancer to cancer. Therefore, we executed correlation and causal network analysis to identify chemotherapy associated immune feature genes, and fortunately identified six co-owned immune feature genes (CD48, GPR65, C3AR1, CD2, CD3E and ARHGAP9) in 10 cancers (BLCA, BRCA, COAD, LUAD, LUSC, OV, PAAD, SKCM, STAD and UCEC). Base on this, we developed a chemotherapy benefit prediction model within six co-owned immune feature genes through random forest classifying (AUC =0.83) in cancers mentioned above, and validated its efficiency in external datasets. In short, our work offers a novel model with a shrinking panel which has the potential to guide optimal chemotherapy in cancer.

Targeting STT3A produces an anti-tumor effect in lung adenocarcinoma by blocking the MAPK and PI3K/AKT signaling pathway.

Background: Glycosylation is crucial for the stability and biological functions of proteins. The aberrant glycosylation of critical proteins plays an important role in multiple cancers, including lung adenocarcinoma (LUAD). STT3 oligosaccharyltransferase complex catalytic subunit A (STT3A) is a major isoform of N-linked glycosyltransferase that catalyzes the glycosylation of various proteins. However, the functions of STT3A in LUAD are still unclear. Methods: The expression profiles of STT3A were initially analyzed in public data sets and then validated by quantitative real-time polymerase chain reaction, Western blot and immunohistochemistry assays in clinical LUAD samples. The overall survival (OS) between patients with high and low STT3A expression was compared using a Kaplan-Meier curve with a log-rank analysis. STT3A was knocked-out using CRISPR/Cas9 and inhibited by NGI-1. Cell Counting Kit-8, colony formation assay, wound-healing, transwell assay, and flow cytometry were performed to assess the cellular functions of STT3A in vitro. A mice xenograft model was established to investigate the effects of STT3A on tumor growth in vivo. Further, the downstream signaling pathways of STT3A were screened by mass spectrometry with a bioinformatics analysis, and the activation of the target pathways were subsequently validated by Western blot. Results: The expression of STT3A was frequently upregulated in LUAD tissues than normal lung tissues. The high expression of STT3A was significantly associated with poor OS in LUAD patients. The knockout or inhibition of STT3A suppressed proliferation, migration, and invasion, and arrested the cell cycle of LUAD cell lines in vitro. Similarly, the knockout or inhibition of STT3A suppressed tumor growth in vivo. In terms of molecular mechanism, STT3A may promote LUAD progression by activating the mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3-kinase and protein kinase B (PI3K/AKT) pathways and regulating the epithelial-mesenchymal transition. Conclusions: STT3A promotes LUAD progression via the MAPK and PI3K/AKT signaling pathways and could serve as a novel prognostic biomarker and potential therapeutic target for LUAD patients.

Decreased expression of EFCC1 and its prognostic value in lung adenocarcinoma.

BACKGROUND: So far, there is a lack of reliable prognostic biomarkers for lung adenocarcinoma (ADC). Initially, we found that EF-hand and coiled-coil domain containing 1 (EFCC1) was a novel gene which was downregulated consistently with the progression of lung ADC in The Cancer Genome Atlas (TCGA) data through bioinformatics analysis. In this study, we aimed to evaluate the prognostic significance of EFCC1 in lung ADC in both TCGA data and clinical samples. METHODS: Firstly, the expression level and prognostic significance of EFCC1 in lung ADC were investigated in TCGA data. Then, the expression level of EFCC1 was validated by qPCR, Western blot, and immunohistochemistry (IHC) in five clinical lung ADC and matched adjacent non-tumor tissues. Finally, the association of EFCC1 expression with clinicopathological characteristics and overall survival (OS) in lung ADC patients was further evaluated in 130 clinical lung ADC samples with tissue microarray (TMA). RESULTS: In TCGA data, we found that decreased mRNA expression (P<0.001), elevated DNA methylation (P<0.001) of EFCC1 in lung ADC samples compared with normal lung samples, and low EFCC1 mRNA expression was associated with poor OS in lung ADC patients (HR =0.856, 95% CI: 0.754-0.970, P=0.015). In five clinical lung ADC and matched adjacent non-tumor tissues, both mRNA and protein levels of EFCC1 were lower in all lung ADC tissues than in their adjacent non-tumor counterparts. In 130 clinical lung ADC samples with TMA, EFCC1 expression was correlated with tumor-node-metastasis (TNM) stages (P=0.040) and lymph node metastasis status (P=0.001). The Kaplan-Meier survival curve revealed that low EFCC1 expression was significantly associated with poor OS in lung ADC patients (P=0.001) and multivariate Cox regression hazard model demonstrated that EFCC1 expression level was an independent prognostic factor for lung ADC patients (HR =0.557, 95% CI: 0.351-0.883, P=0.013). CONCLUSIONS: Our findings suggested that decreased expression of EFCC1 was significantly associated with progression of lung ADC and could serve as a novel prognostic biomarker for lung ADC patients.

Metformin synergistically sensitizes FLT3-ITD-positive acute myeloid leukemia to sorafenib by promoting mTOR-mediated apoptosis and autophagy.

Mutations of Fms-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD), accounting for approximately 30% of patients with acute myeloid leukemia (AML), results in poor therapeutic efficacy and short survival. Sorafenib, an oral multikinase inhibitor, can inhibit FLT3 and improve clinical outcome of FLT3 mutated leukemia. Our current studies have shown that, the antidiabetic drug metformin also exerts anti-leukemic effect by activating p-AMPK and synergistically sensitizes FLT3 mutated AML to sorafenib. Both agents suppress cell proliferation in a dose-dependent manner and induce apoptosis via cell cycle arrest, but does not obviously modulate autophagy marker, light chain 3 (LC3). Mechanistically, in the presence of metformin, the anticancer potential of sorafenib, accompanying with increased LC3 levels, is found to be synergistically enhanced with the remarkably reduced protein expression of the mTOR/p70S6K/4EBP1 pathway, while not appreciably altering cell cycle. Overall, these results show metformin in aid of sorafenib may represent a promising and attractive strategy for the treatment of FLT3-ITD mutated AML.